diff --git a/src/screens/SyncSettingsScreen.tsx b/src/screens/SyncSettingsScreen.tsx
index 6be0070f..87229945 100644
--- a/src/screens/SyncSettingsScreen.tsx
+++ b/src/screens/SyncSettingsScreen.tsx
@@ -178,8 +178,8 @@ const SyncSettingsScreen: React.FC = () => {
           </View>
           <Text style={[styles.cardText, { color: currentTheme.colors.mediumEmphasis }]}>
             {externalSyncActive
-              ? `${externalSyncServices.join(' + ')} is active. Watch progress and library updates are managed by these services instead of Nuvio cloud database.`
-              : 'If Trakt or Simkl sync is enabled, watch progress and library updates will use those services instead of Nuvio cloud database.'}
+              ? `${externalSyncServices.join(' + ')} is active. Watch progress and watched status are managed by these services instead of Nuvio cloud database. Library sync still uses Nuvio cloud.`
+              : 'If Trakt or Simkl sync is enabled, watch progress and watched status will use those services instead of Nuvio cloud database. Library sync still uses Nuvio cloud.'}
           </Text>
         </View>
 
diff --git a/src/services/supabaseSyncService.ts b/src/services/supabaseSyncService.ts
index 635baeb8..1149c79f 100644
--- a/src/services/supabaseSyncService.ts
+++ b/src/services/supabaseSyncService.ts
@@ -7,6 +7,7 @@ import { catalogService, StreamingContent } from './catalogService';
 import { storageService } from './storageService';
 import { watchedService, LocalWatchedItem } from './watchedService';
 import { TraktService } from './traktService';
+import { SimklService } from './simklService';
 
 const SUPABASE_SESSION_KEY = '@supabase:session';
 const DEFAULT_SYNC_DEBOUNCE_MS = 2000;
@@ -123,6 +124,7 @@ class SupabaseSyncService {
   private readonly foregroundPullCooldownMs = 30000;
   private pendingWatchProgressDeleteKeys = new Set<string>();
   private watchProgressDeleteTimer: ReturnType<typeof setTimeout> | null = null;
+  private watchProgressPushedSignatures = new Map<string, string>();
 
   private pendingPushTimers: Record<PushTarget, ReturnType<typeof setTimeout> | null> = {
     plugins: null,
@@ -236,6 +238,7 @@ class SupabaseSyncService {
     }
 
     this.session = null;
+    this.watchProgressPushedSignatures.clear();
     await mmkvStorage.removeItem(SUPABASE_SESSION_KEY);
   }
 
@@ -277,13 +280,15 @@ class SupabaseSyncService {
     await this.pushPluginsFromLocal();
     await this.pushAddonsFromLocal();
 
-    const traktConnected = await this.isTraktConnected();
-    if (traktConnected) {
+    await this.pushLibraryFromLocal();
+    const externalProgressSyncConnected = await this.isExternalProgressSyncConnected();
+    if (externalProgressSyncConnected) {
+      logger.log('[SupabaseSyncService] External sync (Trakt/Simkl) is connected; skipping watch progress/watched-items push, keeping library sync.');
+      logger.log('[SupabaseSyncService] pushAllLocalData: complete');
       return;
     }
 
     await this.pushWatchProgressFromLocal();
-    await this.pushLibraryFromLocal();
     await this.pushWatchedItemsFromLocal();
     logger.log('[SupabaseSyncService] pushAllLocalData: complete');
   }
@@ -296,13 +301,14 @@ class SupabaseSyncService {
       await this.pullPluginsToLocal();
       await this.pullAddonsToLocal();
 
-      const traktConnected = await this.isTraktConnected();
-      if (traktConnected) {
+      await this.pullLibraryToLocal();
+      const externalProgressSyncConnected = await this.isExternalProgressSyncConnected();
+      if (externalProgressSyncConnected) {
+        logger.log('[SupabaseSyncService] External sync (Trakt/Simkl) is connected; skipping watch progress/watched-items pull, keeping library sync.');
         return;
       }
 
       await this.pullWatchProgressToLocal();
-      await this.pullLibraryToLocal();
       await this.pullWatchedItemsToLocal();
     });
     logger.log('[SupabaseSyncService] pullAllToLocal: complete');
@@ -493,9 +499,18 @@ class SupabaseSyncService {
       logger.warn('[SupabaseSyncService] runStartupSync: one or more pull steps failed; skipped startup push-by-design');
     }
 
-    const traktConnected = await this.isTraktConnected();
-    if (traktConnected) {
-      logger.log('[SupabaseSyncService] Trakt is connected; skipping progress/library/watched Supabase sync.');
+    const libraryPullOk = await this.safeRun('pull_library', async () => {
+      await this.withSuppressedPushes(async () => {
+        await this.pullLibraryToLocal();
+      });
+    });
+
+    const externalProgressSyncConnected = await this.isExternalProgressSyncConnected();
+    if (externalProgressSyncConnected) {
+      logger.log('[SupabaseSyncService] External sync (Trakt/Simkl) is connected; skipping watch progress/watched-items Supabase sync (library still synced).');
+      if (!libraryPullOk) {
+        logger.warn('[SupabaseSyncService] runStartupSync: library pull failed while external sync priority is active');
+      }
       return;
     }
 
@@ -505,12 +520,6 @@ class SupabaseSyncService {
       });
     });
 
-    const libraryPullOk = await this.safeRun('pull_library', async () => {
-      await this.withSuppressedPushes(async () => {
-        await this.pullLibraryToLocal();
-      });
-    });
-
     const watchedPullOk = await this.safeRun('pull_watched_items', async () => {
       await this.withSuppressedPushes(async () => {
         await this.pullWatchedItemsToLocal();
@@ -629,8 +638,8 @@ class SupabaseSyncService {
       return;
     }
 
-    const traktConnected = await this.isTraktConnected();
-    if (traktConnected) return;
+    const externalProgressSyncConnected = await this.isExternalProgressSyncConnected();
+    if (externalProgressSyncConnected) return;
 
     try {
       logger.log(`[SupabaseSyncService] flushWatchProgressDeletes: deleting ${keys.length} keys`);
@@ -700,12 +709,12 @@ class SupabaseSyncService {
       return;
     }
 
-    const traktConnected = await this.isTraktConnected();
-    if (traktConnected) {
-      return;
-    }
-
     if (target === 'watch_progress') {
+      const externalProgressSyncConnected = await this.isExternalProgressSyncConnected();
+      if (externalProgressSyncConnected) {
+        logger.log('[SupabaseSyncService] executeScheduledPush: skipping watch_progress due to external sync priority (Trakt/Simkl)');
+        return;
+      }
       await this.pushWatchProgressFromLocal();
       logger.log(`[SupabaseSyncService] executeScheduledPush: target=${target}:done`);
       return;
@@ -716,6 +725,12 @@ class SupabaseSyncService {
       return;
     }
 
+    const externalProgressSyncConnected = await this.isExternalProgressSyncConnected();
+    if (externalProgressSyncConnected) {
+      logger.log('[SupabaseSyncService] executeScheduledPush: skipping watched_items due to external sync priority (Trakt/Simkl)');
+      return;
+    }
+
     await this.pushWatchedItemsFromLocal();
     logger.log(`[SupabaseSyncService] executeScheduledPush: target=${target}:done`);
   }
@@ -745,6 +760,8 @@ class SupabaseSyncService {
   }
 
   private async setSession(session: SupabaseSession): Promise<void> {
+    // Reset per-entry push cache on session changes to avoid cross-account state bleed.
+    this.watchProgressPushedSignatures.clear();
     this.session = session;
     await mmkvStorage.setItem(SUPABASE_SESSION_KEY, JSON.stringify(session));
   }
@@ -775,6 +792,7 @@ class SupabaseSyncService {
     } catch (error) {
       logger.error('[SupabaseSyncService] Failed to refresh session:', error);
       this.session = null;
+      this.watchProgressPushedSignatures.clear();
       await mmkvStorage.removeItem(SUPABASE_SESSION_KEY);
       return false;
     }
@@ -791,6 +809,7 @@ class SupabaseSyncService {
       } catch (error) {
         logger.error('[SupabaseSyncService] Token refresh failed:', error);
         this.session = null;
+        this.watchProgressPushedSignatures.clear();
         await mmkvStorage.removeItem(SUPABASE_SESSION_KEY);
         return null;
       }
@@ -997,6 +1016,22 @@ class SupabaseSyncService {
     };
   }
 
+  private getWatchProgressEntrySignature(value: { currentTime?: number; duration?: number; lastUpdated?: number }): string {
+    return [
+      Number(value.currentTime || 0),
+      Number(value.duration || 0),
+      Number(value.lastUpdated || 0),
+    ].join('|');
+  }
+
+  private buildLocalWatchProgressKey(
+    contentType: 'movie' | 'series',
+    contentId: string,
+    episodeId?: string
+  ): string {
+    return `${contentType}:${contentId}${episodeId ? `:${episodeId}` : ''}`;
+  }
+
   private toStreamingContent(item: LibraryRow): StreamingContent {
     const type = item.content_type === 'movie' ? 'movie' : 'series';
     const posterShape = (item.poster_shape || 'POSTER').toLowerCase() as 'poster' | 'square' | 'landscape';
@@ -1037,6 +1072,19 @@ class SupabaseSyncService {
     }
   }
 
+  private async isSimklConnected(): Promise<boolean> {
+    try {
+      return await SimklService.getInstance().isAuthenticated();
+    } catch {
+      return false;
+    }
+  }
+
+  private async isExternalProgressSyncConnected(): Promise<boolean> {
+    if (await this.isTraktConnected()) return true;
+    return await this.isSimklConnected();
+  }
+
   private async pullPluginsToLocal(): Promise<void> {
     const token = await this.getValidAccessToken();
     if (!token) return;
@@ -1254,11 +1302,10 @@ class SupabaseSyncService {
       const type = row.content_type === 'movie' ? 'movie' : 'series';
       const season = row.season == null ? null : Number(row.season);
       const episode = row.episode == null ? null : Number(row.episode);
-      remoteSet.add(`${type}:${row.content_id}:${season ?? ''}:${episode ?? ''}`);
-
       const episodeId = type === 'series' && season != null && episode != null
         ? `${row.content_id}:${season}:${episode}`
         : undefined;
+      remoteSet.add(this.buildLocalWatchProgressKey(type, row.content_id, episodeId));
 
       const local = await storageService.getWatchProgress(row.content_id, type, episodeId);
       const remoteLastWatched = this.normalizeEpochMs(row.last_watched);
@@ -1284,15 +1331,46 @@ class SupabaseSyncService {
       );
     }
 
-    logger.log(`[SupabaseSyncService] pullWatchProgressToLocal: merged ${(rows || []).length} remote entries (no local prune)`);
+    // Remote-first continue watching: remove local entries that no longer exist remotely.
+    // This intentionally treats the successful remote pull as authoritative.
+    const allLocal = await storageService.getAllWatchProgress();
+    let pruned = 0;
+    for (const [localKey] of Object.entries(allLocal)) {
+      if (remoteSet.has(localKey)) continue;
+
+      const parsed = this.parseWatchProgressKey(localKey);
+      if (!parsed) continue;
+
+      const episodeId = parsed.videoId && parsed.videoId !== parsed.contentId ? parsed.videoId : undefined;
+      await storageService.removeWatchProgress(parsed.contentId, parsed.contentType, episodeId);
+      this.watchProgressPushedSignatures.delete(localKey);
+      pruned += 1;
+    }
+
+    logger.log(`[SupabaseSyncService] pullWatchProgressToLocal: merged=${(rows || []).length} prunedLocalMissing=${pruned}`);
   }
 
   private async pushWatchProgressFromLocal(): Promise<void> {
     const all = await storageService.getAllWatchProgress();
-    const entries: WatchProgressRow[] = Object.entries(all).reduce<WatchProgressRow[]>((acc, [key, value]) => {
+    const nextSeenKeys = new Set<string>();
+    const changedEntries: Array<{ key: string; row: WatchProgressRow; signature: string }> = [];
+
+    for (const [key, value] of Object.entries(all)) {
+      nextSeenKeys.add(key);
+      const signature = this.getWatchProgressEntrySignature(value);
+      if (this.watchProgressPushedSignatures.get(key) === signature) {
+        continue;
+      }
+
       const parsed = this.parseWatchProgressKey(key);
-      if (!parsed) return acc;
-      acc.push({
+      if (!parsed) {
+        continue;
+      }
+
+      changedEntries.push({
+        key,
+        signature,
+        row: {
         content_id: parsed.contentId,
         content_type: parsed.contentType,
         video_id: parsed.videoId,
@@ -1302,11 +1380,30 @@ class SupabaseSyncService {
         duration: this.secondsToMsLong(value.duration),
         last_watched: this.normalizeEpochMs(value.lastUpdated || Date.now()),
         progress_key: parsed.progressKey,
+        },
       });
-      return acc;
-    }, []);
+    }
 
-    await this.callRpc<void>('sync_push_watch_progress', { p_entries: entries });
+    // Prune signatures for entries no longer present locally (deletes are handled separately).
+    for (const existingKey of Array.from(this.watchProgressPushedSignatures.keys())) {
+      if (!nextSeenKeys.has(existingKey)) {
+        this.watchProgressPushedSignatures.delete(existingKey);
+      }
+    }
+
+    if (changedEntries.length === 0) {
+      logger.log('[SupabaseSyncService] pushWatchProgressFromLocal: no changed entries; skipping push');
+      return;
+    }
+
+    await this.callRpc<void>('sync_push_watch_progress', {
+      p_entries: changedEntries.map((entry) => entry.row),
+    });
+
+    for (const entry of changedEntries) {
+      this.watchProgressPushedSignatures.set(entry.key, entry.signature);
+    }
+    logger.log(`[SupabaseSyncService] pushWatchProgressFromLocal: pushedChanged=${changedEntries.length} totalLocal=${Object.keys(all).length}`);
   }
 
   private async pullLibraryToLocal(): Promise<void> {