diff --git a/meshcore_gui/core/shared_data.py b/meshcore_gui/core/shared_data.py
index 1e17dae..a6db5ef 100644
--- a/meshcore_gui/core/shared_data.py
+++ b/meshcore_gui/core/shared_data.py
@@ -77,6 +77,12 @@ class SharedData:
         # Room Server login states: pubkey → {'state': 'ok'|'fail'|'pending'|'logged_out', 'detail': str}
         self.room_login_states: Dict[str, Dict] = {}
 
+        # Known room pubkeys/prefixes (normalised to 12 hex chars).
+        # This is a central, UI-independent registry used by the
+        # MessagesPanel to keep Room Server traffic out of All Messages,
+        # even when the room cards are not yet fully restored.
+        self._known_room_pubkeys: set[str] = set()
+
         # Room message cache: pubkey_prefix (12 hex) → List[Message]
         # Populated from archive on first access per room, then kept in
         # sync by add_message().
@@ -177,9 +183,37 @@ class SharedData:
             return self.device.name
 
     # ------------------------------------------------------------------
-    # Room Server login state
+    # Room Server login state / known room registry
     # ------------------------------------------------------------------
 
+    @staticmethod
+    def _normalise_room_pubkey(pubkey: str) -> str:
+        """Return a comparable room pubkey prefix.
+
+        Normalises a full Room Server pubkey or a shorter prefix to the
+        canonical 12-hex representation used throughout the room-cache
+        logic. Returns an empty string for falsey input.
+        """
+        return (pubkey or '').strip()[:12]
+
+    def register_room_pubkey(self, pubkey: str) -> None:
+        """Register a Room Server pubkey/prefix as known.
+
+        Keeps the registry small and stable by storing only the
+        canonical 12-hex prefix. Safe to call repeatedly.
+        """
+        norm = self._normalise_room_pubkey(pubkey)
+        if not norm:
+            return
+        with self.lock:
+            self._known_room_pubkeys.add(norm)
+
+    def get_known_room_pubkeys(self) -> set[str]:
+        """Return a copy of all centrally known Room Server keys."""
+        with self.lock:
+            return set(self._known_room_pubkeys)
+
+
     def set_room_login_state(
         self, pubkey_prefix: str, state: str, detail: str = "",
     ) -> None:
@@ -195,9 +229,14 @@ class SharedData:
             state:         One of 'pending', 'ok', 'fail', 'logged_out'.
             detail:        Human-readable detail string.
         """
+        norm = self._normalise_room_pubkey(pubkey_prefix)
+        if not norm:
+            return
+
         with self.lock:
+            self._known_room_pubkeys.add(norm)
+
             # Remove overlapping entries (different key length, same room)
-            norm = pubkey_prefix[:12]
             stale = [
                 k for k in self.room_login_states
                 if k != pubkey_prefix and k[:12] == norm
@@ -240,10 +279,14 @@ class SharedData:
         if not self.archive:
             return
 
-        norm = pubkey[:12]
+        norm = self._normalise_room_pubkey(pubkey)
+        if not norm:
+            return
+
         archived = self.archive.get_messages_by_sender_pubkey(norm, limit)
 
         with self.lock:
+            self._known_room_pubkeys.add(norm)
             messages = [Message.from_dict(d) for d in archived]
             self._room_msg_cache[norm] = messages
             debug_print(
@@ -259,7 +302,9 @@ class SharedData:
         Returns:
             List of Message objects (oldest first), or empty list.
         """
-        norm = pubkey[:12]
+        norm = self._normalise_room_pubkey(pubkey)
+        if not norm:
+            return []
         with self.lock:
             return list(self._room_msg_cache.get(norm, []))
 
@@ -559,6 +604,8 @@ class SharedData:
                 k: v.copy()
                 for k, v in self.room_login_states.items()
             },
+            # Centrally known room keys (UI-independent)
+            'known_room_pubkeys': set(self._known_room_pubkeys),
             # Room message cache (archived + live)
             'room_messages': {
                 k: list(v)
diff --git a/meshcore_gui/gui/panels/messages_panel.py b/meshcore_gui/gui/panels/messages_panel.py
index 00fc9ee..a3f26e4 100644
--- a/meshcore_gui/gui/panels/messages_panel.py
+++ b/meshcore_gui/gui/panels/messages_panel.py
@@ -1,6 +1,6 @@
 """Messages panel — filtered message display with channel selection and message input."""
 
-from typing import Callable, Dict, List, Set
+from typing import Callable, Dict, Iterable, List, Set
 
 from nicegui import ui
 
@@ -153,12 +153,30 @@ class MessagesPanel:
 
     # -- Message display -----------------------------------------------
 
+    @staticmethod
+    def _merge_room_pubkeys(
+        ui_room_pubkeys: Set[str] | None,
+        known_room_pubkeys: Iterable[str] | None,
+    ) -> Set[str]:
+        """Merge UI-tracked and centrally known Room Server keys.
+
+        The RoomServerPanel may not yet be fully restored when archived
+        messages are first shown.  The SharedData registry provides a
+        second, UI-independent source of truth for room key prefixes.
+        """
+        merged: Set[str] = set()
+        if ui_room_pubkeys:
+            merged.update(pk for pk in ui_room_pubkeys if pk)
+        if known_room_pubkeys:
+            merged.update(pk for pk in known_room_pubkeys if pk)
+        return merged
+
     @staticmethod
     def _is_room_message(msg: Message, room_pubkeys: Set[str]) -> bool:
         """Return True if *msg* belongs to a Room Server.
 
         Matches when the message's ``sender_pubkey`` prefix-matches
-        any tracked room pubkey (same logic as RoomServerPanel).
+        any tracked or centrally known room pubkey.
         """
         if not msg.sender_pubkey or not room_pubkeys:
             return False
@@ -195,7 +213,10 @@ class MessagesPanel:
         if not self._container:
             return
 
-        room_pks = room_pubkeys or set()
+        room_pks = self._merge_room_pubkeys(
+            room_pubkeys,
+            data.get('known_room_pubkeys'),
+        )
         channel_names = {ch['idx']: ch['name'] for ch in last_channels}
         contacts = data.get('contacts', {})
         messages: List[Message] = data['messages']