diff --git a/src/services/supabaseSyncService.ts b/src/services/supabaseSyncService.ts
index 09816061..6d511ed5 100644
--- a/src/services/supabaseSyncService.ts
+++ b/src/services/supabaseSyncService.ts
@@ -1038,27 +1038,55 @@ class SupabaseSyncService {
     videoId: string;
     progressKey: string;
   } | null {
-    const parts = key.split(':');
-    if (parts.length < 2) return null;
+    // Key format from buildWpKeyString: "{type}:{contentId}" or "{type}:{contentId}:{episodeId}"
+    // contentId may contain colons (e.g., "tmdb:1399", "kitsu:12345")
+    // episodeId ends with ":{season}:{episode}" digits
+    const typeIdx = key.indexOf(':');
+    if (typeIdx < 0) return null;
 
-    const contentType: 'movie' | 'series' = parts[0] === 'movie' ? 'movie' : 'series';
-    const contentId = parts[1];
-    const episodeId = parts.length > 2 ? parts.slice(2).join(':') : '';
+    const typePart = key.substring(0, typeIdx);
+    if (typePart !== 'movie' && typePart !== 'series') return null;
+    const contentType: 'movie' | 'series' = typePart;
+
+    const rest = key.substring(typeIdx + 1);
+    if (!rest) return null;
+
+    // Extract content ID: detect known prefixed patterns (tmdb:NNN, kitsu:NNN),
+    // otherwise take the first colon-free segment (e.g., tt12345).
+    const cidPrefixMatch = rest.match(/^((?:tmdb|kitsu):\d+)/);
+    const contentId = cidPrefixMatch ? cidPrefixMatch[1] : rest.split(':')[0];
+    if (!contentId) return null;
+
+    const afterContentId = rest.substring(contentId.length);
+
+    if (!afterContentId || afterContentId === ':') {
+      // No episode info (movie or series-level)
+      return {
+        contentType,
+        contentId,
+        season: null,
+        episode: null,
+        videoId: contentId,
+        progressKey: contentId,
+      };
+    }
+
+    // Strip leading ":" to get episodeId
+    const episodeId = afterContentId.substring(1);
+
+    // Extract season:episode from the end of episodeId
     let season: number | null = null;
     let episode: number | null = null;
-
-    if (episodeId) {
-      const match = episodeId.match(/:(\d+):(\d+)$/);
-      if (match) {
-        season = Number(match[1]);
-        episode = Number(match[2]);
-      }
+    const seMatch = episodeId.match(/:(\d+):(\d+)$/);
+    if (seMatch) {
+      season = Number(seMatch[1]);
+      episode = Number(seMatch[2]);
     }
 
     const videoId = episodeId || contentId;
-    const progressKey = contentType === 'movie'
-      ? contentId
-      : (season != null && episode != null ? `${contentId}_s${season}e${episode}` : `${contentId}_${videoId}`);
+    const progressKey = season != null && episode != null
+      ? `${contentId}_s${season}e${episode}`
+      : `${contentId}_${episodeId}`;
 
     return {
       contentType,
@@ -1365,7 +1393,7 @@ class SupabaseSyncService {
       const season = row.season == null ? null : Number(row.season);
       const episode = row.episode == null ? null : Number(row.episode);
       const episodeId = type === 'series' && season != null && episode != null
-        ? `${row.content_id}:${season}:${episode}`
+        ? (row.video_id && row.video_id !== row.content_id ? row.video_id : `${row.content_id}:${season}:${episode}`)
         : undefined;
       remoteSet.add(this.buildLocalWatchProgressKey(type, row.content_id, episodeId));