diff --git a/frontend/src/components/chat/ChatMessageView.tsx b/frontend/src/components/chat/ChatMessageView.tsx
index 21a6d01..85c27fd 100644
--- a/frontend/src/components/chat/ChatMessageView.tsx
+++ b/frontend/src/components/chat/ChatMessageView.tsx
@@ -17,6 +17,16 @@ const ChatMessageView: React.FC = () => {
   const queryClient = useQueryClient();
   const messagesEndRef = useRef<HTMLDivElement>(null);
   const [input, setInput] = useState('');
+  const prevActiveRef = useRef(false);
+
+  // Invalidate messages immediately when this room + panel becomes active
+  useEffect(() => {
+    const active = !!selectedRoomToken && chatPanelOpen;
+    if (active && !prevActiveRef.current) {
+      queryClient.invalidateQueries({ queryKey: ['nextcloud', 'messages', selectedRoomToken] });
+    }
+    prevActiveRef.current = active;
+  }, [selectedRoomToken, chatPanelOpen, queryClient]);
 
   const room = rooms.find((r) => r.token === selectedRoomToken);
 
diff --git a/frontend/src/components/shared/NotificationBell.tsx b/frontend/src/components/shared/NotificationBell.tsx
index b8e91a2..eab4e8c 100644
--- a/frontend/src/components/shared/NotificationBell.tsx
+++ b/frontend/src/components/shared/NotificationBell.tsx
@@ -26,6 +26,27 @@ import type { Notification, NotificationSchwere } from '../../types/notification
 
 const POLL_INTERVAL_MS = 15_000; // 15 seconds
 
+function playNotificationSound() {
+  try {
+    const ctx = new AudioContext();
+    const oscillator = ctx.createOscillator();
+    const gain = ctx.createGain();
+    oscillator.connect(gain);
+    gain.connect(ctx.destination);
+    oscillator.type = 'sine';
+    oscillator.frequency.value = 600;
+    const now = ctx.currentTime;
+    gain.gain.setValueAtTime(0, now);
+    gain.gain.linearRampToValueAtTime(0.3, now + 0.02);
+    gain.gain.linearRampToValueAtTime(0, now + 0.15);
+    oscillator.start(now);
+    oscillator.stop(now + 0.15);
+    oscillator.onended = () => ctx.close();
+  } catch {
+    // Audio blocked before first user interaction — fail silently
+  }
+}
+
 /**
  * Only allow window.open for URLs whose origin matches the current app origin.
  * External-looking URLs (different host or protocol-relative) are rejected to
@@ -83,6 +104,9 @@ const NotificationBell: React.FC = () => {
 
       // Find notifications we haven't seen before
       const newOnes = unread.filter((n) => !knownIdsRef.current!.has(n.id));
+      if (newOnes.length > 0) {
+        playNotificationSound();
+      }
       newOnes.forEach((n) => {
         knownIdsRef.current!.add(n.id);
         const severity = n.schwere === 'fehler' ? 'error' : n.schwere === 'warnung' ? 'warning' : 'info';
diff --git a/frontend/src/contexts/ChatContext.tsx b/frontend/src/contexts/ChatContext.tsx
index a2c91fb..75973c7 100644
--- a/frontend/src/contexts/ChatContext.tsx
+++ b/frontend/src/contexts/ChatContext.tsx
@@ -1,5 +1,5 @@
-import React, { createContext, useContext, useState, useCallback, ReactNode } from 'react';
-import { useQuery } from '@tanstack/react-query';
+import React, { createContext, useContext, useState, useCallback, useEffect, useRef, ReactNode } from 'react';
+import { useQuery, useQueryClient } from '@tanstack/react-query';
 import { nextcloudApi } from '../services/nextcloud';
 import { useLayout } from './LayoutContext';
 import type { NextcloudConversation } from '../types/nextcloud.types';
@@ -21,6 +21,17 @@ interface ChatProviderProps {
 export const ChatProvider: React.FC<ChatProviderProps> = ({ children }) => {
   const [selectedRoomToken, setSelectedRoomToken] = useState<string | null>(null);
   const { chatPanelOpen } = useLayout();
+  const queryClient = useQueryClient();
+  const prevPanelOpenRef = useRef(chatPanelOpen);
+
+  // Invalidate rooms/connection when panel opens so data is fresh immediately
+  useEffect(() => {
+    if (chatPanelOpen && !prevPanelOpenRef.current) {
+      queryClient.invalidateQueries({ queryKey: ['nextcloud', 'connection'] });
+      queryClient.invalidateQueries({ queryKey: ['nextcloud', 'rooms'] });
+    }
+    prevPanelOpenRef.current = chatPanelOpen;
+  }, [chatPanelOpen, queryClient]);
 
   const { data: connData } = useQuery({
     queryKey: ['nextcloud', 'connection'],
diff --git a/sync/src/db.ts b/sync/src/db.ts
index b626076..1f454a5 100644
--- a/sync/src/db.ts
+++ b/sync/src/db.ts
@@ -69,7 +69,9 @@ export async function syncToDatabase(
       const profileResult = await client.query<{ user_id: string }>(
         `SELECT mp.user_id
          FROM mitglieder_profile mp
-         WHERE mp.fdisk_standesbuch_nr = $1`,
+         JOIN users u ON u.id = mp.user_id
+         WHERE mp.fdisk_standesbuch_nr = $1
+           AND u.last_login_at IS NOT NULL`,
         [member.standesbuchNr]
       );
 
@@ -78,18 +80,20 @@ export async function syncToDatabase(
       if (profileResult.rows.length > 0) {
         userId = profileResult.rows[0].user_id;
       } else {
-        // Fallback: match by name (case-insensitive)
+        // Fallback: match by name (case-insensitive), only logged-in users
         const nameResult = await client.query<{ id: string }>(
           `SELECT u.id
            FROM users u
            JOIN mitglieder_profile mp ON mp.user_id = u.id
            WHERE LOWER(u.given_name) = LOWER($1)
              AND LOWER(u.family_name) = LOWER($2)
-           LIMIT 1`,
+             AND u.last_login_at IS NOT NULL`,
           [member.vorname, member.zuname]
         );
 
-        if (nameResult.rows.length > 0) {
+        if (nameResult.rows.length > 1) {
+          log(`WARN: skipping ${member.vorname} ${member.zuname} (Standesbuch-Nr ${member.standesbuchNr}) — duplicate name match (${nameResult.rows.length} users)`);
+        } else if (nameResult.rows.length === 1) {
           userId = nameResult.rows[0].id;
           // Store the Standesbuch-Nr now that we found a match
           await client.query(