Be much, much clearer about room server ops. Closes #78.

Order room server messages by sender timestamp, not packet-receipt time

app/main.py

@@ -17,6 +17,7 @@ from app.frontend_static import (
 )
 from app.radio import RadioDisconnectedError
 from app.radio_sync import (
+    stop_background_contact_reconciliation,
     stop_message_polling,
     stop_periodic_advert,
     stop_periodic_sync,
@@ -95,6 +96,7 @@ async def lifespan(app: FastAPI):
             pass
     await fanout_manager.stop_all()
     await radio_manager.stop_connection_monitor()
+    await stop_background_contact_reconciliation()
     await stop_message_polling()
     await stop_periodic_advert()
     await stop_periodic_sync()

app/radio.py

@@ -548,11 +548,14 @@ class RadioManager:
 
     async def disconnect(self) -> None:
         """Disconnect from the radio."""
+        from app.radio_sync import stop_background_contact_reconciliation
+
         clear_keys()
         self._reset_reconnect_error_broadcasts()
         if self._meshcore is None:
             return
 
+        await stop_background_contact_reconciliation()
         await self._acquire_operation_lock("disconnect", blocking=True)
         try:
             mc = self._meshcore

app/radio_sync.py

@@ -166,6 +166,9 @@ async def pause_polling():
 # Background task handle
 _sync_task: asyncio.Task | None = None
 
+# Startup/background contact reconciliation task handle
+_contact_reconcile_task: asyncio.Task | None = None
+
 # Periodic maintenance check interval in seconds (5 minutes)
 SYNC_INTERVAL = 300
 
@@ -266,30 +269,7 @@ async def sync_and_offload_contacts(mc: MeshCore) -> dict:
                 remove_result = await mc.commands.remove_contact(contact_data)
                 if remove_result.type == EventType.OK:
                     removed += 1
-
-                    # LIBRARY INTERNAL FIXUP: The MeshCore library's
-                    # commands.remove_contact() sends the remove command over
-                    # the wire but does NOT update the library's in-memory
-                    # contact cache (mc._contacts). This is a gap in the
-                    # library — there's no public API to clear a single
-                    # contact from the cache, and the library only refreshes
-                    # it on a full get_contacts() call.
-                    #
-                    # Why this matters: sync_recent_contacts_to_radio() uses
-                    # mc.get_contact_by_key_prefix() to check whether a
-                    # contact is already loaded on the radio. That method
-                    # searches mc._contacts. If we don't evict the removed
-                    # contact from the cache here, get_contact_by_key_prefix()
-                    # will still find it and skip the add_contact() call —
-                    # meaning contacts never get loaded back onto the radio
-                    # after offload. The result: no DM ACKs, degraded routing
-                    # for potentially minutes until the next periodic sync
-                    # refreshes the cache from the (now-empty) radio.
-                    #
-                    # We access mc._contacts directly because the library
-                    # exposes it as a read-only property (mc.contacts) with
-                    # no removal API. The dict is keyed by public_key string.
-                    mc._contacts.pop(public_key, None)
+                    _evict_removed_contact_from_library_cache(mc, public_key)
                 else:
                     logger.warning(
                         "Failed to remove contact %s: %s", public_key[:12], remove_result.payload
@@ -461,28 +441,28 @@ async def ensure_default_channels() -> None:
 
 
 async def sync_and_offload_all(mc: MeshCore) -> dict:
-    """Sync and offload both contacts and channels, then ensure defaults exist."""
+    """Run fast startup sync, then background contact reconcile."""
     logger.info("Starting full radio sync and offload")
 
     # Contact on_radio is legacy/stale metadata. Clear it during the offload/reload
     # cycle so old rows stop claiming radio residency we do not actively track.
     await ContactRepository.clear_on_radio_except([])
 
-    contacts_result = await sync_and_offload_contacts(mc)
+    contacts_result = await sync_contacts_from_radio(mc)
     channels_result = await sync_and_offload_channels(mc)
 
     # Ensure default channels exist
     await ensure_default_channels()
 
-    # Reload favorites plus a working-set fill back onto the radio immediately.
-    # Pass mc directly since the caller already holds the radio operation lock
-    # (asyncio.Lock is not reentrant).
-    reload_result = await sync_recent_contacts_to_radio(force=True, mc=mc)
+    start_background_contact_reconciliation(
+        initial_radio_contacts=contacts_result.get("radio_contacts", {}),
+        expected_mc=mc,
+    )
 
     return {
         "contacts": contacts_result,
         "channels": channels_result,
-        "reloaded": reload_result,
+        "contact_reconcile_started": True,
     }
 
 
@@ -1036,6 +1016,270 @@ async def stop_periodic_sync():
 # Throttling for contact sync to radio
 _last_contact_sync: float = 0.0
 CONTACT_SYNC_THROTTLE_SECONDS = 30  # Don't sync more than once per 30 seconds
+CONTACT_RECONCILE_BATCH_SIZE = 2
+CONTACT_RECONCILE_YIELD_SECONDS = 0.05
+
+
+def _evict_removed_contact_from_library_cache(mc: MeshCore, public_key: str) -> None:
+    """Keep the library's contact cache consistent after a successful removal."""
+    # LIBRARY INTERNAL FIXUP: The MeshCore library's remove_contact() sends the
+    # remove command over the wire but does NOT update the library's in-memory
+    # contact cache (mc._contacts). This is a gap in the library — there's no
+    # public API to clear a single contact from the cache, and the library only
+    # refreshes it on a full get_contacts() call.
+    #
+    # Why this matters: contact sync and targeted ensure/load paths use
+    # mc.get_contact_by_key_prefix() to check whether a contact is already
+    # loaded on the radio. That method searches mc._contacts. If we don't evict
+    # the removed contact from the cache here, later syncs will still find it
+    # and skip add_contact() calls, leaving the radio without the contact even
+    # though the app thinks it is resident.
+    mc._contacts.pop(public_key, None)
+
+
+def _normalize_radio_contacts_payload(contacts: dict | None) -> dict[str, dict]:
+    """Return radio contacts keyed by normalized lowercase full public key."""
+    normalized: dict[str, dict] = {}
+    for public_key, contact_data in (contacts or {}).items():
+        normalized[str(public_key).lower()] = contact_data
+    return normalized
+
+
+async def sync_contacts_from_radio(mc: MeshCore) -> dict:
+    """Pull contacts from the radio and persist them to the database without removing them."""
+    synced = 0
+
+    try:
+        result = await mc.commands.get_contacts()
+
+        if result is None or result.type == EventType.ERROR:
+            logger.error(
+                "Failed to get contacts from radio: %s. "
+                "If you see this repeatedly, the radio may be visible on the "
+                "serial/TCP/BLE port but not responding to commands. Check for "
+                "another process with the serial port open (other RemoteTerm "
+                "instances, serial monitors, etc.), verify the firmware is "
+                "up-to-date and in client mode (not repeater), or try a "
+                "power cycle.",
+                result,
+            )
+            return {"synced": 0, "radio_contacts": {}, "error": str(result)}
+
+        contacts = _normalize_radio_contacts_payload(result.payload)
+        logger.info("Found %d contacts on radio", len(contacts))
+
+        for public_key, contact_data in contacts.items():
+            await ContactRepository.upsert(
+                ContactUpsert.from_radio_dict(public_key, contact_data, on_radio=False)
+            )
+            asyncio.create_task(
+                _reconcile_contact_messages_background(
+                    public_key,
+                    contact_data.get("adv_name"),
+                )
+            )
+            synced += 1
+
+        logger.info("Synced %d contacts from radio snapshot", synced)
+        return {"synced": synced, "radio_contacts": contacts}
+    except Exception as e:
+        logger.error("Error during contact snapshot sync: %s", e)
+        return {"synced": synced, "radio_contacts": {}, "error": str(e)}
+
+
+async def _reconcile_radio_contacts_in_background(
+    *,
+    initial_radio_contacts: dict[str, dict],
+    expected_mc: MeshCore,
+) -> None:
+    """Converge radio contacts toward the desired favorites+recents working set."""
+    radio_contacts = dict(initial_radio_contacts)
+    removed = 0
+    loaded = 0
+    failed = 0
+
+    try:
+        while True:
+            if not radio_manager.is_connected or radio_manager.meshcore is not expected_mc:
+                logger.info("Stopping background contact reconcile: radio transport changed")
+                break
+
+            selected_contacts = await get_contacts_selected_for_radio_sync()
+            desired_contacts = {
+                contact.public_key.lower(): contact
+                for contact in selected_contacts
+                if len(contact.public_key) >= 64
+            }
+            removable_keys = [key for key in radio_contacts if key not in desired_contacts]
+            missing_contacts = [
+                contact for key, contact in desired_contacts.items() if key not in radio_contacts
+            ]
+
+            if not removable_keys and not missing_contacts:
+                logger.info(
+                    "Background contact reconcile complete: %d contacts on radio working set",
+                    len(radio_contacts),
+                )
+                break
+
+            progressed = False
+            try:
+                async with radio_manager.radio_operation(
+                    "background_contact_reconcile",
+                    blocking=False,
+                ) as mc:
+                    if mc is not expected_mc:
+                        logger.info(
+                            "Stopping background contact reconcile: radio transport changed"
+                        )
+                        break
+
+                    budget = CONTACT_RECONCILE_BATCH_SIZE
+                    selected_contacts = await get_contacts_selected_for_radio_sync()
+                    desired_contacts = {
+                        contact.public_key.lower(): contact
+                        for contact in selected_contacts
+                        if len(contact.public_key) >= 64
+                    }
+
+                    for public_key in list(radio_contacts):
+                        if budget <= 0:
+                            break
+                        if public_key in desired_contacts:
+                            continue
+
+                        remove_payload = (
+                            mc.get_contact_by_key_prefix(public_key[:12])
+                            or radio_contacts.get(public_key)
+                            or {"public_key": public_key}
+                        )
+                        try:
+                            remove_result = await mc.commands.remove_contact(remove_payload)
+                        except Exception as exc:
+                            failed += 1
+                            budget -= 1
+                            logger.warning(
+                                "Error removing contact %s during background reconcile: %s",
+                                public_key[:12],
+                                exc,
+                            )
+                            continue
+
+                        budget -= 1
+                        if remove_result.type == EventType.OK:
+                            radio_contacts.pop(public_key, None)
+                            _evict_removed_contact_from_library_cache(mc, public_key)
+                            removed += 1
+                            progressed = True
+                        else:
+                            failed += 1
+                            logger.warning(
+                                "Failed to remove contact %s during background reconcile: %s",
+                                public_key[:12],
+                                remove_result.payload,
+                            )
+
+                    if budget > 0:
+                        for public_key, contact in desired_contacts.items():
+                            if budget <= 0:
+                                break
+                            if public_key in radio_contacts:
+                                continue
+
+                            if mc.get_contact_by_key_prefix(public_key[:12]):
+                                radio_contacts[public_key] = {"public_key": public_key}
+                                continue
+
+                            try:
+                                add_payload = contact.to_radio_dict()
+                                add_result = await mc.commands.add_contact(add_payload)
+                            except Exception as exc:
+                                failed += 1
+                                budget -= 1
+                                logger.warning(
+                                    "Error adding contact %s during background reconcile: %s",
+                                    public_key[:12],
+                                    exc,
+                                    exc_info=True,
+                                )
+                                continue
+
+                            budget -= 1
+                            if add_result.type == EventType.OK:
+                                radio_contacts[public_key] = add_payload
+                                loaded += 1
+                                progressed = True
+                            else:
+                                failed += 1
+                                reason = add_result.payload
+                                hint = ""
+                                if reason is None:
+                                    hint = (
+                                        " (no response from radio — if this repeats, check for "
+                                        "serial port contention from another process or try a "
+                                        "power cycle)"
+                                    )
+                                logger.warning(
+                                    "Failed to add contact %s during background reconcile: %s%s",
+                                    public_key[:12],
+                                    reason,
+                                    hint,
+                                )
+            except RadioOperationBusyError:
+                logger.debug("Background contact reconcile yielding: radio busy")
+
+            await asyncio.sleep(CONTACT_RECONCILE_YIELD_SECONDS)
+            if not progressed:
+                continue
+    except asyncio.CancelledError:
+        logger.info("Background contact reconcile task cancelled")
+        raise
+    except Exception as exc:
+        logger.error("Background contact reconcile failed: %s", exc, exc_info=True)
+    finally:
+        if removed > 0 or loaded > 0 or failed > 0:
+            logger.info(
+                "Background contact reconcile summary: removed %d, loaded %d, failed %d",
+                removed,
+                loaded,
+                failed,
+            )
+
+
+def start_background_contact_reconciliation(
+    *,
+    initial_radio_contacts: dict[str, dict],
+    expected_mc: MeshCore,
+) -> None:
+    """Start or replace the background contact reconcile task for the current radio."""
+    global _contact_reconcile_task
+
+    if _contact_reconcile_task is not None and not _contact_reconcile_task.done():
+        _contact_reconcile_task.cancel()
+
+    _contact_reconcile_task = asyncio.create_task(
+        _reconcile_radio_contacts_in_background(
+            initial_radio_contacts=initial_radio_contacts,
+            expected_mc=expected_mc,
+        )
+    )
+    logger.info(
+        "Started background contact reconcile for %d radio contact(s)",
+        len(initial_radio_contacts),
+    )
+
+
+async def stop_background_contact_reconciliation() -> None:
+    """Stop the background contact reconcile task."""
+    global _contact_reconcile_task
+
+    if _contact_reconcile_task and not _contact_reconcile_task.done():
+        _contact_reconcile_task.cancel()
+        try:
+            await _contact_reconcile_task
+        except asyncio.CancelledError:
+            pass
+    _contact_reconcile_task = None
 
 
 async def get_contacts_selected_for_radio_sync() -> list[Contact]:

app/routers/server_control.py

@@ -62,7 +62,7 @@ def _login_rejected_message(label: str) -> str:
 def _login_send_failed_message(label: str) -> str:
     return (
         f"The login request could not be sent to the {label}. "
-        f"The control panel is still available, but authenticated actions may fail until a login succeeds."
+        f"You're free to attempt interaction; try logging in again if authenticated actions fail."
     )
 
 
@@ -70,7 +70,7 @@ def _login_timeout_message(label: str) -> str:
     return (
         f"No login confirmation was heard from the {label}. "
         "That can mean the password was wrong or the reply was missed in transit. "
-        "The control panel is still available; try logging in again if authenticated actions fail."
+        "You're free to attempt interaction; try logging in again if authenticated actions fail."
     )
 
 

frontend/src/App.tsx

@@ -1,4 +1,4 @@
-import { useEffect, useCallback, useRef, useState } from 'react';
+import { useEffect, useCallback, useRef, useState, useMemo } from 'react';
 import { api } from './api';
 import { takePrefetchOrFetch } from './prefetch';
 import { useWebSocket } from './useWebSocket';
@@ -24,6 +24,7 @@ import { DistanceUnitProvider } from './contexts/DistanceUnitContext';
 import { messageContainsMention } from './utils/messageParser';
 import { getStateKey } from './utils/conversationState';
 import type { Conversation, Message, RawPacket } from './types';
+import { CONTACT_TYPE_ROOM } from './types';
 
 interface ChannelUnreadMarker {
   channelId: string;
@@ -251,6 +252,21 @@ export function App() {
   } = useConversationMessages(activeConversation, targetMessageId);
   removeConversationMessagesRef.current = removeConversationMessages;
 
+  // Room servers replay stored history as a burst of DMs, all arriving with similar received_at
+  // but spanning a wide range of sender_timestamps. Sort by sender_timestamp for room contacts
+  // so the display reflects the original send order rather than our radio's receipt order.
+  const activeContactIsRoom =
+    activeConversation?.type === 'contact' &&
+    contacts.find((c) => c.public_key === activeConversation.id)?.type === CONTACT_TYPE_ROOM;
+  const sortedMessages = useMemo(() => {
+    if (!activeContactIsRoom || messages.length === 0) return messages;
+    return [...messages].sort((a, b) => {
+      const aTs = a.sender_timestamp ?? a.received_at;
+      const bTs = b.sender_timestamp ?? b.received_at;
+      return aTs !== bTs ? aTs - bTs : a.id - b.id;
+    });
+  }, [activeContactIsRoom, messages]);
+
   const {
     unreadCounts,
     mentions,
@@ -427,7 +443,7 @@ export function App() {
     config,
     health,
     favorites,
-    messages,
+    messages: sortedMessages,
     messagesLoading,
     loadingOlder,
     hasOlderMessages,

frontend/src/components/RepeaterDashboard.tsx

@@ -5,6 +5,7 @@ import { Button } from './ui/button';
 import { Bell, Route, Star, Trash2 } from 'lucide-react';
 import { DirectTraceIcon } from './DirectTraceIcon';
 import { RepeaterLogin } from './RepeaterLogin';
+import { ServerLoginStatusBanner } from './ServerLoginStatusBanner';
 import { useRememberedServerPassword } from '../hooks/useRememberedServerPassword';
 import { useRepeaterDashboard } from '../hooks/useRepeaterDashboard';
 import { isFavorite } from '../utils/favorites';
@@ -69,6 +70,7 @@ export function RepeaterDashboard({
     loggedIn,
     loginLoading,
     loginError,
+    lastLoginAttempt,
     paneData,
     paneStates,
     consoleHistory,
@@ -249,6 +251,14 @@ export function RepeaterDashboard({
           />
         ) : (
           <div className="space-y-4">
+            <ServerLoginStatusBanner
+              attempt={lastLoginAttempt}
+              loading={loginLoading}
+              canRetryPassword={password.trim().length > 0}
+              onRetryPassword={() => handleRepeaterLogin(password)}
+              onRetryBlank={handleRepeaterGuestLogin}
+              blankRetryLabel="Retry Existing-Access Login"
+            />
             {/* Top row: Telemetry + Radio Settings | Node Info + Neighbors */}
             <div className="grid grid-cols-1 gap-4 md:grid-cols-2 md:items-stretch">
               <div className="flex flex-col gap-4">

frontend/src/components/RoomServerPanel.tsx

@@ -16,7 +16,13 @@ import { AclPane } from './repeater/RepeaterAclPane';
 import { LppTelemetryPane } from './repeater/RepeaterLppTelemetryPane';
 import { ConsolePane } from './repeater/RepeaterConsolePane';
 import { RepeaterLogin } from './RepeaterLogin';
+import { ServerLoginStatusBanner } from './ServerLoginStatusBanner';
 import { useRememberedServerPassword } from '../hooks/useRememberedServerPassword';
+import {
+  buildServerLoginAttemptFromError,
+  buildServerLoginAttemptFromResponse,
+  type ServerLoginAttemptState,
+} from '../utils/serverLoginState';
 
 interface RoomServerPanelProps {
   contact: Contact;
@@ -61,6 +67,7 @@ export function RoomServerPanel({ contact, onAuthenticatedChange }: RoomServerPa
   const [loginLoading, setLoginLoading] = useState(false);
   const [loginError, setLoginError] = useState<string | null>(null);
   const [authenticated, setAuthenticated] = useState(false);
+  const [lastLoginAttempt, setLastLoginAttempt] = useState<ServerLoginAttemptState | null>(null);
   const [advancedOpen, setAdvancedOpen] = useState(false);
   const [paneData, setPaneData] = useState<RoomPaneData>({
     status: null,
@@ -75,6 +82,7 @@ export function RoomServerPanel({ contact, onAuthenticatedChange }: RoomServerPa
     setLoginLoading(false);
     setLoginError(null);
     setAuthenticated(false);
+    setLastLoginAttempt(null);
     setAdvancedOpen(false);
     setPaneData({
       status: null,
@@ -129,26 +137,32 @@ export function RoomServerPanel({ contact, onAuthenticatedChange }: RoomServerPa
   );
 
   const performLogin = useCallback(
-    async (password: string) => {
+    async (nextPassword: string, method: 'password' | 'blank') => {
       if (loginLoading) return;
 
       setLoginLoading(true);
       setLoginError(null);
       try {
-        const result = await api.roomLogin(contact.public_key, password);
+        const result = await api.roomLogin(contact.public_key, nextPassword);
+        setLastLoginAttempt(buildServerLoginAttemptFromResponse(method, result, 'room server'));
         setAuthenticated(true);
         if (result.authenticated) {
-          toast.success('Room login confirmed');
+          toast.success('Login confirmed by the room server.');
         } else {
-          toast.warning('Room login not confirmed', {
-            description: result.message ?? 'Room login was not confirmed',
+          toast.warning("Couldn't confirm room login", {
+            description:
+              result.message ??
+              'No confirmation came back from the room server. You can still open tools and try again.',
           });
         }
       } catch (err) {
         const message = err instanceof Error ? err.message : 'Unknown error';
+        setLastLoginAttempt(buildServerLoginAttemptFromError(method, message, 'room server'));
         setAuthenticated(true);
         setLoginError(message);
-        toast.error('Room login failed', { description: message });
+        toast.error('Room login request failed', {
+          description: `${message}. You can still open tools and retry the login from here.`,
+        });
       } finally {
         setLoginLoading(false);
       }
@@ -157,15 +171,15 @@ export function RoomServerPanel({ contact, onAuthenticatedChange }: RoomServerPa
   );
 
   const handleLogin = useCallback(
-    async (password: string) => {
-      await performLogin(password);
-      persistAfterLogin(password);
+    async (nextPassword: string) => {
+      await performLogin(nextPassword, 'password');
+      persistAfterLogin(nextPassword);
     },
     [performLogin, persistAfterLogin]
   );
 
   const handleLoginAsGuest = useCallback(async () => {
-    await performLogin('');
+    await performLogin('', 'blank');
     persistAfterLogin('');
   }, [performLogin, persistAfterLogin]);
 
@@ -207,6 +221,8 @@ export function RoomServerPanel({ contact, onAuthenticatedChange }: RoomServerPa
   );
 
   const panelTitle = useMemo(() => contact.name || contact.public_key.slice(0, 12), [contact]);
+  const showLoginFailureState =
+    lastLoginAttempt !== null && lastLoginAttempt.outcome !== 'confirmed';
 
   if (!authenticated) {
     return (
@@ -236,7 +252,7 @@ export function RoomServerPanel({ contact, onAuthenticatedChange }: RoomServerPa
             onLoginAsGuest={handleLoginAsGuest}
             description="Log in with the room password or use ACL/guest access to enter this room server"
             passwordPlaceholder="Room server password..."
-            guestLabel="Login with ACL / Guest"
+            guestLabel="Login with Existing Access / Guest"
           />
         </div>
       </div>
@@ -245,15 +261,52 @@ export function RoomServerPanel({ contact, onAuthenticatedChange }: RoomServerPa
 
   return (
     <section className="border-b border-border bg-muted/20 px-4 py-3">
-      <div className="flex justify-end">
-        <Button
-          type="button"
-          variant="outline"
-          size="sm"
-          onClick={() => setAdvancedOpen((prev) => !prev)}
-        >
-          {advancedOpen ? 'Hide Tools' : 'Show Tools'}
-        </Button>
+      <div className="space-y-3">
+        {showLoginFailureState ? (
+          <ServerLoginStatusBanner
+            attempt={lastLoginAttempt}
+            loading={loginLoading}
+            canRetryPassword={password.trim().length > 0}
+            onRetryPassword={() => handleLogin(password)}
+            onRetryBlank={handleLoginAsGuest}
+            blankRetryLabel="Retry Existing-Access Login"
+            showRetryActions={false}
+          />
+        ) : null}
+        <div className="flex flex-wrap items-center justify-between gap-2">
+          {showLoginFailureState ? (
+            <div className="flex flex-wrap gap-2">
+              <Button
+                type="button"
+                variant="outline"
+                size="sm"
+                onClick={() => void handleLogin(password)}
+                disabled={loginLoading || password.trim().length === 0}
+              >
+                Retry Password Login
+              </Button>
+              <Button
+                type="button"
+                variant="outline"
+                size="sm"
+                onClick={handleLoginAsGuest}
+                disabled={loginLoading}
+              >
+                Retry Existing-Access Login
+              </Button>
+            </div>
+          ) : (
+            <div />
+          )}
+          <Button
+            type="button"
+            variant="outline"
+            size="sm"
+            onClick={() => setAdvancedOpen((prev) => !prev)}
+          >
+            {advancedOpen ? 'Hide Tools' : 'Show Tools'}
+          </Button>
+        </div>
       </div>
       <Sheet open={advancedOpen} onOpenChange={setAdvancedOpen}>
         <SheetContent side="right" className="w-full sm:max-w-4xl p-0 flex flex-col">
@@ -269,15 +322,6 @@ export function RoomServerPanel({ contact, onAuthenticatedChange }: RoomServerPa
                 <h2 className="truncate text-base font-semibold">Room Server Tools</h2>
                 <p className="text-sm text-muted-foreground">{panelTitle}</p>
               </div>
-              <Button
-                type="button"
-                variant="outline"
-                onClick={handleLoginAsGuest}
-                disabled={loginLoading}
-                className="self-start sm:self-auto"
-              >
-                Refresh ACL Login
-              </Button>
             </div>
           </div>
           <div className="flex-1 overflow-y-auto p-4">

frontend/src/components/ServerLoginStatusBanner.tsx

@@ -0,0 +1,76 @@
+import { Button } from './ui/button';
+import type { ServerLoginAttemptState } from '../utils/serverLoginState';
+import { getServerLoginAttemptTone } from '../utils/serverLoginState';
+import { cn } from '../lib/utils';
+
+interface ServerLoginStatusBannerProps {
+  attempt: ServerLoginAttemptState | null;
+  loading: boolean;
+  canRetryPassword: boolean;
+  onRetryPassword: () => Promise<void> | void;
+  onRetryBlank: () => Promise<void> | void;
+  passwordRetryLabel?: string;
+  blankRetryLabel?: string;
+  showRetryActions?: boolean;
+}
+
+export function ServerLoginStatusBanner({
+  attempt,
+  loading,
+  canRetryPassword,
+  onRetryPassword,
+  onRetryBlank,
+  passwordRetryLabel = 'Retry Password Login',
+  blankRetryLabel = 'Retry Existing-Access Login',
+  showRetryActions = true,
+}: ServerLoginStatusBannerProps) {
+  if (attempt?.outcome === 'confirmed') {
+    return null;
+  }
+
+  const tone = getServerLoginAttemptTone(attempt);
+  const shouldShowActions = showRetryActions;
+  const toneClassName =
+    tone === 'success'
+      ? 'border-success/30 bg-success/10 text-success'
+      : tone === 'warning'
+        ? 'border-warning/30 bg-warning/10 text-warning'
+        : tone === 'destructive'
+          ? 'border-destructive/30 bg-destructive/10 text-destructive'
+          : 'border-border bg-muted/40 text-foreground';
+
+  return (
+    <div className={cn('rounded-md border px-4 py-3', toneClassName)}>
+      <div className="flex flex-col gap-3 sm:flex-row sm:items-start sm:justify-between">
+        <div className="min-w-0 space-y-1">
+          <p className="text-sm font-medium">
+            {attempt?.summary ?? 'No server login attempt has been recorded in this view yet.'}
+          </p>
+          {attempt?.details && <p className="text-xs opacity-90">{attempt.details}</p>}
+        </div>
+        {shouldShowActions ? (
+          <div className="flex flex-wrap gap-2">
+            <Button
+              type="button"
+              variant="outline"
+              size="sm"
+              onClick={() => void onRetryPassword()}
+              disabled={loading || !canRetryPassword}
+            >
+              {passwordRetryLabel}
+            </Button>
+            <Button
+              type="button"
+              variant="outline"
+              size="sm"
+              onClick={() => void onRetryBlank()}
+              disabled={loading}
+            >
+              {blankRetryLabel}
+            </Button>
+          </div>
+        ) : null}
+      </div>
+    </div>
+  );
+}

frontend/src/hooks/useRememberedServerPassword.ts

@@ -2,12 +2,13 @@ import { useCallback, useEffect, useMemo, useState } from 'react';
 
 type ServerLoginKind = 'repeater' | 'room';
 
-const STORAGE_KEY_PREFIX = 'remoteterm-server-password';
-
 type StoredPassword = {
   password: string;
 };
 
+const STORAGE_KEY_PREFIX = 'remoteterm-server-password';
+const inMemoryPasswords = new Map<string, StoredPassword>();
+
 function getStorageKey(kind: ServerLoginKind, publicKey: string): string {
   return `${STORAGE_KEY_PREFIX}:${kind}:${publicKey}`;
 }
@@ -33,37 +34,46 @@ export function useRememberedServerPassword(kind: ServerLoginKind, publicKey: st
 
   useEffect(() => {
     const stored = loadStoredPassword(kind, publicKey);
-    if (!stored) {
-      setPassword('');
+    if (stored) {
+      setPassword(stored.password);
+      setRememberPassword(true);
+      return;
+    }
+
+    const inMemoryStored = inMemoryPasswords.get(storageKey);
+    if (inMemoryStored) {
+      setPassword(inMemoryStored.password);
       setRememberPassword(false);
       return;
     }
-    setPassword(stored.password);
-    setRememberPassword(true);
-  }, [kind, publicKey]);
+
+    setPassword('');
+    setRememberPassword(false);
+  }, [kind, publicKey, storageKey]);
 
   const persistAfterLogin = useCallback(
     (submittedPassword: string) => {
+      const trimmedPassword = submittedPassword.trim();
+      if (!trimmedPassword) {
+        return;
+      }
+
+      inMemoryPasswords.set(storageKey, { password: trimmedPassword });
+
       if (!rememberPassword) {
         try {
           localStorage.removeItem(storageKey);
         } catch {
           // localStorage may be unavailable
         }
-        setPassword('');
-        return;
+      } else {
+        try {
+          localStorage.setItem(storageKey, JSON.stringify({ password: trimmedPassword }));
+        } catch {
+          // localStorage may be unavailable
+        }
       }
 
-      const trimmedPassword = submittedPassword.trim();
-      if (!trimmedPassword) {
-        return;
-      }
-
-      try {
-        localStorage.setItem(storageKey, JSON.stringify({ password: trimmedPassword }));
-      } catch {
-        // localStorage may be unavailable
-      }
       setPassword(trimmedPassword);
     },
     [rememberPassword, storageKey]

frontend/src/hooks/useRepeaterDashboard.ts

@@ -15,6 +15,11 @@ import type {
   RepeaterLppTelemetryResponse,
   CommandResponse,
 } from '../types';
+import {
+  buildServerLoginAttemptFromError,
+  buildServerLoginAttemptFromResponse,
+  type ServerLoginAttemptState,
+} from '../utils/serverLoginState';
 
 const MAX_RETRIES = 3;
 const RETRY_DELAY_MS = 2000;
@@ -41,6 +46,7 @@ interface PaneData {
 interface RepeaterDashboardCacheEntry {
   loggedIn: boolean;
   loginError: string | null;
+  lastLoginAttempt: ServerLoginAttemptState | null;
   paneData: PaneData;
   paneStates: Record<PaneName, PaneState>;
   consoleHistory: ConsoleEntry[];
@@ -119,6 +125,7 @@ function getCachedState(publicKey: string | null): RepeaterDashboardCacheEntry |
   return {
     loggedIn: cached.loggedIn,
     loginError: cached.loginError,
+    lastLoginAttempt: cached.lastLoginAttempt,
     paneData: clonePaneData(cached.paneData),
     paneStates: normalizePaneStates(cached.paneStates),
     consoleHistory: cloneConsoleHistory(cached.consoleHistory),
@@ -130,6 +137,7 @@ function cacheState(publicKey: string, entry: RepeaterDashboardCacheEntry) {
   repeaterDashboardCache.set(publicKey, {
     loggedIn: entry.loggedIn,
     loginError: entry.loginError,
+    lastLoginAttempt: entry.lastLoginAttempt,
     paneData: clonePaneData(entry.paneData),
     paneStates: normalizePaneStates(entry.paneStates),
     consoleHistory: cloneConsoleHistory(entry.consoleHistory),
@@ -173,6 +181,7 @@ export interface UseRepeaterDashboardResult {
   loggedIn: boolean;
   loginLoading: boolean;
   loginError: string | null;
+  lastLoginAttempt: ServerLoginAttemptState | null;
   paneData: PaneData;
   paneStates: Record<PaneName, PaneState>;
   consoleHistory: ConsoleEntry[];
@@ -203,6 +212,9 @@ export function useRepeaterDashboard(
   const [loggedIn, setLoggedIn] = useState(cachedState?.loggedIn ?? false);
   const [loginLoading, setLoginLoading] = useState(false);
   const [loginError, setLoginError] = useState<string | null>(cachedState?.loginError ?? null);
+  const [lastLoginAttempt, setLastLoginAttempt] = useState<ServerLoginAttemptState | null>(
+    cachedState?.lastLoginAttempt ?? null
+  );
 
   const [paneData, setPaneData] = useState<PaneData>(
     cachedState?.paneData ?? createInitialPaneData
@@ -243,11 +255,20 @@ export function useRepeaterDashboard(
     cacheState(conversationId, {
       loggedIn,
       loginError,
+      lastLoginAttempt,
       paneData,
       paneStates,
       consoleHistory,
     });
-  }, [consoleHistory, conversationId, loggedIn, loginError, paneData, paneStates]);
+  }, [
+    consoleHistory,
+    conversationId,
+    loggedIn,
+    loginError,
+    lastLoginAttempt,
+    paneData,
+    paneStates,
+  ]);
 
   useEffect(() => {
     paneDataRef.current = paneData;
@@ -267,12 +288,14 @@ export function useRepeaterDashboard(
       const publicKey = getPublicKey();
       if (!publicKey) return;
       const conversationId = publicKey;
+      const method = password.trim().length > 0 ? 'password' : 'blank';
 
       setLoginLoading(true);
       setLoginError(null);
       try {
         const result = await api.repeaterLogin(publicKey, password);
         if (activeIdRef.current !== conversationId) return;
+        setLastLoginAttempt(buildServerLoginAttemptFromResponse(method, result, 'repeater'));
         setLoggedIn(true);
         if (!result.authenticated) {
           const msg = result.message ?? 'Repeater login was not confirmed';
@@ -282,6 +305,7 @@ export function useRepeaterDashboard(
       } catch (err) {
         if (activeIdRef.current !== conversationId) return;
         const msg = err instanceof Error ? err.message : 'Login failed';
+        setLastLoginAttempt(buildServerLoginAttemptFromError(method, msg, 'repeater'));
         setLoggedIn(true);
         setLoginError(msg);
         toast.error('Login request failed', {
@@ -475,6 +499,7 @@ export function useRepeaterDashboard(
     loggedIn,
     loginLoading,
     loginError,
+    lastLoginAttempt,
     paneData,
     paneStates,
     consoleHistory,

frontend/src/test/repeaterDashboard.test.tsx

@@ -11,6 +11,7 @@ const mockHook: {
   loggedIn: false,
   loginLoading: false,
   loginError: null,
+  lastLoginAttempt: null,
   paneData: {
     status: null,
     nodeInfo: null,

frontend/src/test/roomServerPanel.test.tsx

@@ -56,22 +56,84 @@ describe('RoomServerPanel', () => {
       status: 'timeout',
       authenticated: false,
       message:
-        'No login confirmation was heard from the room server. The control panel is still available; try logging in again if authenticated actions fail.',
+        "No login confirmation was heard from the room server. You're free to try sending messages; try logging in again if authenticated actions fail.",
     });
     const onAuthenticatedChange = vi.fn();
 
     render(<RoomServerPanel contact={roomContact} onAuthenticatedChange={onAuthenticatedChange} />);
 
-    fireEvent.click(screen.getByText('Login with ACL / Guest'));
+    fireEvent.click(screen.getByText('Login with Existing Access / Guest'));
 
     await waitFor(() => {
       expect(screen.getByText('Show Tools')).toBeInTheDocument();
     });
     expect(screen.getByText('Show Tools')).toBeInTheDocument();
-    expect(mockToast.warning).toHaveBeenCalledWith('Room login not confirmed', {
+    expect(screen.getByText('Retry Existing-Access Login')).toBeInTheDocument();
+    expect(mockToast.warning).toHaveBeenCalledWith("Couldn't confirm room login", {
       description:
-        'No login confirmation was heard from the room server. The control panel is still available; try logging in again if authenticated actions fail.',
+        "No login confirmation was heard from the room server. You're free to try sending messages; try logging in again if authenticated actions fail.",
     });
     expect(onAuthenticatedChange).toHaveBeenLastCalledWith(true);
   });
+
+  it('retains the last password for one-click retry after unlocking the panel', async () => {
+    mockApi.roomLogin
+      .mockResolvedValueOnce({
+        status: 'timeout',
+        authenticated: false,
+        message: 'No reply heard',
+      })
+      .mockResolvedValueOnce({
+        status: 'ok',
+        authenticated: true,
+        message: null,
+      });
+
+    render(<RoomServerPanel contact={roomContact} />);
+
+    fireEvent.change(screen.getByLabelText('Repeater password'), {
+      target: { value: 'secret-room-password' },
+    });
+    fireEvent.click(screen.getByText('Login with Password'));
+
+    await waitFor(() => {
+      expect(screen.getByText('Retry Password Login')).toBeInTheDocument();
+    });
+
+    fireEvent.click(screen.getByText('Retry Password Login'));
+
+    await waitFor(() => {
+      expect(mockApi.roomLogin).toHaveBeenNthCalledWith(
+        1,
+        roomContact.public_key,
+        'secret-room-password'
+      );
+      expect(mockApi.roomLogin).toHaveBeenNthCalledWith(
+        2,
+        roomContact.public_key,
+        'secret-room-password'
+      );
+    });
+  });
+
+  it('shows only a success toast after a confirmed login', async () => {
+    mockApi.roomLogin.mockResolvedValueOnce({
+      status: 'ok',
+      authenticated: true,
+      message: null,
+    });
+
+    render(<RoomServerPanel contact={roomContact} />);
+
+    fireEvent.click(screen.getByText('Login with Existing Access / Guest'));
+
+    await waitFor(() => {
+      expect(screen.getByText('Show Tools')).toBeInTheDocument();
+    });
+
+    expect(screen.queryByText('Login confirmed by the room server.')).not.toBeInTheDocument();
+    expect(screen.queryByText('Retry Password Login')).not.toBeInTheDocument();
+    expect(screen.queryByText('Retry Existing-Access Login')).not.toBeInTheDocument();
+    expect(mockToast.success).toHaveBeenCalledWith('Login confirmed by the room server.');
+  });
 });

frontend/src/test/useRememberedServerPassword.test.ts

@@ -8,70 +8,24 @@ describe('useRememberedServerPassword', () => {
     localStorage.clear();
   });
 
-  it('loads remembered passwords from localStorage', () => {
-    localStorage.setItem(
-      'remoteterm-server-password:repeater:abc123',
-      JSON.stringify({ password: 'stored-secret' })
+  it('restores the last in-memory password when local remember is disabled', () => {
+    const { result, unmount } = renderHook(() =>
+      useRememberedServerPassword('room', 'aa'.repeat(32))
     );
 
-    const { result } = renderHook(() => useRememberedServerPassword('repeater', 'abc123'));
-
-    expect(result.current.password).toBe('stored-secret');
-    expect(result.current.rememberPassword).toBe(true);
-  });
-
-  it('stores passwords after login when remember is enabled', () => {
-    const { result } = renderHook(() => useRememberedServerPassword('room', 'room-key'));
-
     act(() => {
-      result.current.setRememberPassword(true);
+      result.current.setPassword('room-secret');
+      result.current.persistAfterLogin('room-secret');
     });
 
-    act(() => {
-      result.current.persistAfterLogin('  hello  ');
-    });
+    expect(result.current.password).toBe('room-secret');
+    unmount();
 
-    expect(localStorage.getItem('remoteterm-server-password:room:room-key')).toBe(
-      JSON.stringify({ password: 'hello' })
-    );
-    expect(result.current.password).toBe('hello');
-  });
-
-  it('clears stored passwords when login is done with remember disabled', () => {
-    localStorage.setItem(
-      'remoteterm-server-password:repeater:abc123',
-      JSON.stringify({ password: 'stored-secret' })
+    const { result: remounted } = renderHook(() =>
+      useRememberedServerPassword('room', 'aa'.repeat(32))
     );
 
-    const { result } = renderHook(() => useRememberedServerPassword('repeater', 'abc123'));
-
-    act(() => {
-      result.current.setRememberPassword(false);
-    });
-
-    act(() => {
-      result.current.persistAfterLogin('new-secret');
-    });
-
-    expect(localStorage.getItem('remoteterm-server-password:repeater:abc123')).toBeNull();
-    expect(result.current.password).toBe('');
-  });
-
-  it('preserves remembered passwords on guest login when remember stays enabled', () => {
-    localStorage.setItem(
-      'remoteterm-server-password:room:room-key',
-      JSON.stringify({ password: 'stored-secret' })
-    );
-
-    const { result } = renderHook(() => useRememberedServerPassword('room', 'room-key'));
-
-    act(() => {
-      result.current.persistAfterLogin('');
-    });
-
-    expect(localStorage.getItem('remoteterm-server-password:room:room-key')).toBe(
-      JSON.stringify({ password: 'stored-secret' })
-    );
-    expect(result.current.password).toBe('stored-secret');
+    expect(remounted.current.password).toBe('room-secret');
+    expect(remounted.current.rememberPassword).toBe(false);
   });
 });

frontend/src/test/useRepeaterDashboard.test.ts

@@ -74,6 +74,8 @@ describe('useRepeaterDashboard', () => {
 
     expect(result.current.loggedIn).toBe(true);
     expect(result.current.loginError).toBe(null);
+    expect(result.current.lastLoginAttempt?.heardBack).toBe(true);
+    expect(result.current.lastLoginAttempt?.outcome).toBe('confirmed');
     expect(mockApi.repeaterLogin).toHaveBeenCalledWith(REPEATER_KEY, 'secret');
   });
 
@@ -92,6 +94,8 @@ describe('useRepeaterDashboard', () => {
 
     expect(result.current.loggedIn).toBe(true);
     expect(result.current.loginError).toBe('Auth failed');
+    expect(result.current.lastLoginAttempt?.heardBack).toBe(true);
+    expect(result.current.lastLoginAttempt?.outcome).toBe('not_confirmed');
     expect(mockToast.error).toHaveBeenCalledWith('Login not confirmed', {
       description: 'Auth failed',
     });
@@ -125,6 +129,8 @@ describe('useRepeaterDashboard', () => {
 
     expect(result.current.loggedIn).toBe(true);
     expect(result.current.loginError).toBe('Network error');
+    expect(result.current.lastLoginAttempt?.heardBack).toBe(false);
+    expect(result.current.lastLoginAttempt?.outcome).toBe('request_failed');
     expect(mockToast.error).toHaveBeenCalledWith('Login request failed', {
       description:
         'Network error. The dashboard is still available, but repeater operations may fail until a login succeeds.',

frontend/src/utils/serverLoginState.ts

@@ -0,0 +1,107 @@
+import type { RepeaterLoginResponse } from '../types';
+
+export type ServerLoginMethod = 'password' | 'blank';
+
+export type ServerLoginAttemptState =
+  | {
+      method: ServerLoginMethod;
+      outcome: 'confirmed';
+      summary: string;
+      details: string | null;
+      heardBack: true;
+      at: number;
+    }
+  | {
+      method: ServerLoginMethod;
+      outcome: 'not_confirmed';
+      summary: string;
+      details: string | null;
+      heardBack: boolean;
+      at: number;
+    }
+  | {
+      method: ServerLoginMethod;
+      outcome: 'request_failed';
+      summary: string;
+      details: string | null;
+      heardBack: false;
+      at: number;
+    };
+
+export function getServerLoginMethodLabel(
+  method: ServerLoginMethod,
+  blankLabel = 'existing-access'
+): string {
+  return method === 'password' ? 'password' : blankLabel;
+}
+
+export function getServerLoginAttemptTone(
+  attempt: ServerLoginAttemptState | null
+): 'success' | 'warning' | 'destructive' | 'muted' {
+  if (!attempt) return 'muted';
+  if (attempt.outcome === 'confirmed') return 'success';
+  if (attempt.outcome === 'not_confirmed') return 'warning';
+  return 'destructive';
+}
+
+export function buildServerLoginAttemptFromResponse(
+  method: ServerLoginMethod,
+  result: RepeaterLoginResponse,
+  entityLabel: string
+): ServerLoginAttemptState {
+  const methodLabel = getServerLoginMethodLabel(method);
+  const at = Date.now();
+  const target = `the ${entityLabel}`;
+
+  if (result.authenticated) {
+    return {
+      method,
+      outcome: 'confirmed',
+      summary: `Login confirmed by ${target}.`,
+      details: null,
+      heardBack: true,
+      at,
+    };
+  }
+
+  if (result.status === 'timeout') {
+    return {
+      method,
+      outcome: 'not_confirmed',
+      summary: `We couldn't confirm the login.`,
+      details:
+        result.message ??
+        `No confirmation came back from ${target} after the ${methodLabel} login attempt.`,
+      heardBack: false,
+      at,
+    };
+  }
+
+  return {
+    method,
+    outcome: 'not_confirmed',
+    summary: `Login was not confirmed.`,
+    details:
+      result.message ??
+      `${target} responded, but did not confirm the ${methodLabel} login attempt.`,
+    heardBack: true,
+    at,
+  };
+}
+
+export function buildServerLoginAttemptFromError(
+  method: ServerLoginMethod,
+  message: string,
+  entityLabel: string
+): ServerLoginAttemptState {
+  const methodLabel = getServerLoginMethodLabel(method);
+  const target = `the ${entityLabel}`;
+  return {
+    method,
+    outcome: 'request_failed',
+    summary: `We couldn't send the login request.`,
+    details: `${target} never acknowledged the ${methodLabel} login attempt. ${message}`,
+    heardBack: false,
+    at: Date.now(),
+  };
+}

tests/test_radio_sync.py

@@ -5,12 +5,14 @@ contact/channel sync operations, and default channel management.
 """
 
 import asyncio
+from contextlib import asynccontextmanager
 from unittest.mock import AsyncMock, MagicMock, call, patch
 
 import pytest
 from meshcore import EventType
 from meshcore.events import Event
 
+import app.radio_sync as radio_sync
 from app.models import Favorite
 from app.radio import RadioManager, radio_manager
 from app.radio_sync import (
@@ -36,8 +38,6 @@ from app.repository import (
 @pytest.fixture(autouse=True)
 def reset_sync_state():
     """Reset polling pause state, sync timestamp, and radio_manager before/after each test."""
-    import app.radio_sync as radio_sync
-
     prev_mc = radio_manager._meshcore
     prev_lock = radio_manager._operation_lock
     prev_max_channels = radio_manager.max_channels
@@ -45,12 +45,20 @@ def reset_sync_state():
     prev_slot_by_key = radio_manager._channel_slot_by_key.copy()
     prev_key_by_slot = radio_manager._channel_key_by_slot.copy()
     prev_pending_channel_key_by_slot = radio_manager._pending_message_channel_key_by_slot.copy()
+    prev_contact_reconcile_task = radio_sync._contact_reconcile_task
 
     radio_sync._polling_pause_count = 0
     radio_sync._last_contact_sync = 0.0
     yield
+    if (
+        radio_sync._contact_reconcile_task is not None
+        and radio_sync._contact_reconcile_task is not prev_contact_reconcile_task
+        and not radio_sync._contact_reconcile_task.done()
+    ):
+        radio_sync._contact_reconcile_task.cancel()
     radio_sync._polling_pause_count = 0
     radio_sync._last_contact_sync = 0.0
+    radio_sync._contact_reconcile_task = prev_contact_reconcile_task
     radio_manager._meshcore = prev_mc
     radio_manager._operation_lock = prev_lock
     radio_manager.max_channels = prev_max_channels
@@ -433,7 +441,7 @@ class TestSyncAndOffloadAll:
     """Test session-local contact radio residency reset behavior."""
 
     @pytest.mark.asyncio
-    async def test_clears_stale_contact_on_radio_flags_before_reload(self, test_db):
+    async def test_clears_stale_contact_on_radio_flags_before_background_reconcile(self, test_db):
         await _insert_contact(KEY_A, "Alice", on_radio=True)
         await _insert_contact(KEY_B, "Bob", on_radio=True)
 
@@ -441,8 +449,8 @@ class TestSyncAndOffloadAll:
 
         with (
             patch(
-                "app.radio_sync.sync_and_offload_contacts",
-                new=AsyncMock(return_value={"synced": 0, "removed": 0}),
+                "app.radio_sync.sync_contacts_from_radio",
+                new=AsyncMock(return_value={"synced": 0, "radio_contacts": {}}),
             ),
             patch(
                 "app.radio_sync.sync_and_offload_channels",
@@ -450,8 +458,7 @@ class TestSyncAndOffloadAll:
             ),
             patch("app.radio_sync.ensure_default_channels", new=AsyncMock()),
             patch(
-                "app.radio_sync.sync_recent_contacts_to_radio",
-                new=AsyncMock(return_value={"loaded": 0, "already_on_radio": 0, "failed": 0}),
+                "app.radio_sync.start_background_contact_reconciliation",
             ),
         ):
             await sync_and_offload_all(mock_mc)
@@ -461,6 +468,30 @@ class TestSyncAndOffloadAll:
         assert alice is not None and alice.on_radio is False
         assert bob is not None and bob.on_radio is False
 
+    @pytest.mark.asyncio
+    async def test_starts_background_contact_reconcile_with_radio_snapshot(self, test_db):
+        mock_mc = MagicMock()
+        radio_contacts = {KEY_A: {"public_key": KEY_A}}
+
+        with (
+            patch(
+                "app.radio_sync.sync_contacts_from_radio",
+                new=AsyncMock(return_value={"synced": 1, "radio_contacts": radio_contacts}),
+            ),
+            patch(
+                "app.radio_sync.sync_and_offload_channels",
+                new=AsyncMock(return_value={"synced": 0, "cleared": 0}),
+            ),
+            patch("app.radio_sync.ensure_default_channels", new=AsyncMock()),
+            patch("app.radio_sync.start_background_contact_reconciliation") as mock_start,
+        ):
+            result = await sync_and_offload_all(mock_mc)
+
+        mock_start.assert_called_once_with(
+            initial_radio_contacts=radio_contacts, expected_mc=mock_mc
+        )
+        assert result["contact_reconcile_started"] is True
+
     @pytest.mark.asyncio
     async def test_advert_fill_skips_repeaters(self, test_db):
         """Recent advert fallback only considers non-repeaters."""
@@ -1036,6 +1067,98 @@ class TestSyncAndOffloadContacts:
         assert KEY_A in mock_mc._contacts
 
 
+class TestBackgroundContactReconcile:
+    """Test the yielding background contact reconcile loop."""
+
+    @pytest.mark.asyncio
+    async def test_rechecks_desired_set_before_deleting_contact(self, test_db):
+        await _insert_contact(KEY_A, "Alice", last_contacted=2000)
+        await _insert_contact(KEY_B, "Bob", last_contacted=1000)
+        alice = await ContactRepository.get_by_key(KEY_A)
+        bob = await ContactRepository.get_by_key(KEY_B)
+        assert alice is not None
+        assert bob is not None
+
+        mock_mc = MagicMock()
+        mock_mc.is_connected = True
+        mock_mc.get_contact_by_key_prefix = MagicMock(return_value=None)
+        mock_mc.commands.remove_contact = AsyncMock(return_value=MagicMock(type=EventType.OK))
+        mock_mc.commands.add_contact = AsyncMock(return_value=MagicMock(type=EventType.OK))
+        radio_manager._meshcore = mock_mc
+
+        @asynccontextmanager
+        async def _radio_operation(*args, **kwargs):
+            del args, kwargs
+            yield mock_mc
+
+        with (
+            patch.object(
+                radio_sync.radio_manager,
+                "radio_operation",
+                side_effect=lambda *args, **kwargs: _radio_operation(*args, **kwargs),
+            ),
+            patch(
+                "app.radio_sync.get_contacts_selected_for_radio_sync",
+                side_effect=[[bob], [alice, bob], [alice, bob]],
+            ),
+            patch("app.radio_sync.asyncio.sleep", new=AsyncMock()),
+        ):
+            await radio_sync._reconcile_radio_contacts_in_background(
+                initial_radio_contacts={KEY_A: {"public_key": KEY_A}},
+                expected_mc=mock_mc,
+            )
+
+        mock_mc.commands.remove_contact.assert_not_called()
+        mock_mc.commands.add_contact.assert_awaited_once()
+        payload = mock_mc.commands.add_contact.call_args.args[0]
+        assert payload["public_key"] == KEY_B
+
+    @pytest.mark.asyncio
+    async def test_yields_radio_lock_every_two_contact_operations(self, test_db):
+        await _insert_contact(KEY_A, "Alice", last_contacted=3000)
+        await _insert_contact(KEY_B, "Bob", last_contacted=2000)
+        extra_key = "cc" * 32
+        await _insert_contact(extra_key, "Carol", last_contacted=1000)
+
+        mock_mc = MagicMock()
+        mock_mc.is_connected = True
+        mock_mc.get_contact_by_key_prefix = MagicMock(return_value=None)
+        mock_mc.commands.remove_contact = AsyncMock(return_value=MagicMock(type=EventType.OK))
+        mock_mc.commands.add_contact = AsyncMock()
+        radio_manager._meshcore = mock_mc
+
+        acquire_count = 0
+
+        @asynccontextmanager
+        async def _radio_operation(*args, **kwargs):
+            del args, kwargs
+            nonlocal acquire_count
+            acquire_count += 1
+            yield mock_mc
+
+        with (
+            patch.object(
+                radio_sync.radio_manager,
+                "radio_operation",
+                side_effect=lambda *args, **kwargs: _radio_operation(*args, **kwargs),
+            ),
+            patch("app.radio_sync.get_contacts_selected_for_radio_sync", return_value=[]),
+            patch("app.radio_sync.asyncio.sleep", new=AsyncMock()),
+        ):
+            await radio_sync._reconcile_radio_contacts_in_background(
+                initial_radio_contacts={
+                    KEY_A: {"public_key": KEY_A},
+                    KEY_B: {"public_key": KEY_B},
+                    extra_key: {"public_key": extra_key},
+                },
+                expected_mc=mock_mc,
+            )
+
+        assert acquire_count == 2
+        assert mock_mc.commands.remove_contact.await_count == 3
+        mock_mc.commands.add_contact.assert_not_called()
+
+
 class TestSyncAndOffloadChannels:
     """Test sync_and_offload_channels: pull channels from radio, save to DB, clear from radio."""