diff --git a/app/AGENTS.md b/app/AGENTS.md
index 214ac41..7888741 100644
--- a/app/AGENTS.md
+++ b/app/AGENTS.md
@@ -362,6 +362,16 @@ packet, `packet_processor.py` handles the complete flow:
 export, unknown contact), `on_contact_message` handles DMs from the MeshCore library's
 `CONTACT_MSG_RECV` event. DB deduplication prevents double-storage when both paths fire.
 
+**Prefix-stored DMs (edge case)**: A rare scenario can occur when the radio can decrypt
+a DM (contact is on the radio) but the server cannot (private key not exported or
+contact not yet known server-side). The `CONTACT_MSG_RECV` payload may only include a
+pubkey prefix. If the full key isn't known yet, the message is stored with the prefix
+as `conversation_key`. When a full contact key becomes known (via advertisement or
+radio sync), the server attempts to **claim** those prefix messages and upgrade them
+to the full key. Claims only occur when the prefix matches exactly one contact to
+avoid mis-attribution in large contact sets. Until claimed, these DMs will not show
+in the UI because conversations are keyed by full public keys.
+
 **Outgoing DMs**: Outgoing direct messages are only sent via the app's REST API
 (`POST /api/messages/direct`), which stores the plaintext directly in the database.
 No decryption is needed for outgoing DMs. The real-time packet processor may also see
diff --git a/app/migrations.py b/app/migrations.py
index d3cb5b5..dc99ce7 100644
--- a/app/migrations.py
+++ b/app/migrations.py
@@ -993,3 +993,4 @@ async def _migrate_015_fix_null_sender_timestamp(conn: aiosqlite.Connection) ->
         )
 
     await conn.commit()
+
diff --git a/app/packet_processor.py b/app/packet_processor.py
index 2fc4869..7377441 100644
--- a/app/packet_processor.py
+++ b/app/packet_processor.py
@@ -685,6 +685,13 @@ async def _process_advertisement(
     }
 
     await ContactRepository.upsert(contact_data)
+    claimed = await MessageRepository.claim_prefix_messages(advert.public_key.lower())
+    if claimed > 0:
+        logger.info(
+            "Claimed %d prefix DM message(s) for contact %s",
+            claimed,
+            advert.public_key[:12],
+        )
 
     # Broadcast contact update to connected clients
     broadcast_event(
diff --git a/app/radio_sync.py b/app/radio_sync.py
index 1e32ab7..d8969fc 100644
--- a/app/radio_sync.py
+++ b/app/radio_sync.py
@@ -18,7 +18,7 @@ from meshcore import EventType
 
 from app.models import Contact
 from app.radio import radio_manager
-from app.repository import AppSettingsRepository, ChannelRepository, ContactRepository
+from app.repository import AppSettingsRepository, ChannelRepository, ContactRepository, MessageRepository
 
 logger = logging.getLogger(__name__)
 
@@ -95,6 +95,13 @@ async def sync_and_offload_contacts() -> dict:
             await ContactRepository.upsert(
                 Contact.from_radio_dict(public_key, contact_data, on_radio=False)
             )
+            claimed = await MessageRepository.claim_prefix_messages(public_key.lower())
+            if claimed > 0:
+                logger.info(
+                    "Claimed %d prefix DM message(s) for contact %s",
+                    claimed,
+                    public_key[:12],
+                )
             synced += 1
 
             # Remove from radio
diff --git a/app/repository.py b/app/repository.py
index fcfe504..cd4f3fc 100644
--- a/app/repository.py
+++ b/app/repository.py
@@ -390,7 +390,11 @@ class MessageRepository:
         cursor = await db.conn.execute(
             """UPDATE messages SET conversation_key = ?
                WHERE type = 'PRIV' AND length(conversation_key) < 64
-               AND ? LIKE conversation_key || '%'""",
+               AND ? LIKE conversation_key || '%'
+               AND (
+                   SELECT COUNT(*) FROM contacts
+                   WHERE public_key LIKE messages.conversation_key || '%'
+               ) = 1""",
             (lower_key, lower_key),
         )
         await db.conn.commit()
diff --git a/frontend/src/useWebSocket.ts b/frontend/src/useWebSocket.ts
index 2c0ea14..1f04221 100644
--- a/frontend/src/useWebSocket.ts
+++ b/frontend/src/useWebSocket.ts
@@ -60,6 +60,10 @@ export function useWebSocket(options: UseWebSocketOptions) {
     ws.onopen = () => {
       console.log('WebSocket connected');
       setConnected(true);
+      if (reconnectTimeoutRef.current) {
+        clearTimeout(reconnectTimeoutRef.current);
+        reconnectTimeoutRef.current = null;
+      }
     };
 
     ws.onclose = () => {
@@ -68,6 +72,9 @@ export function useWebSocket(options: UseWebSocketOptions) {
       wsRef.current = null;
 
       // Reconnect after 3 seconds
+      if (reconnectTimeoutRef.current) {
+        clearTimeout(reconnectTimeoutRef.current);
+      }
       reconnectTimeoutRef.current = window.setTimeout(() => {
         console.log('Attempting WebSocket reconnect...');
         connect();
@@ -146,6 +153,7 @@ export function useWebSocket(options: UseWebSocketOptions) {
       clearInterval(pingInterval);
       if (reconnectTimeoutRef.current) {
         clearTimeout(reconnectTimeoutRef.current);
+        reconnectTimeoutRef.current = null;
       }
       if (wsRef.current) {
         wsRef.current.close();