Through your testing above, is it duplicating the same poster each time? If so, try deleting the collection again and:
- After deleting it, head to Settings → [Select Server Name] → Troubleshooting.
- Optimize the database and clean bundles.
- Recreate the collection manually, this time leaving out the movie whose poster was duplicated.
If the collection poster is created from four unique posters this time try adding the problematic movie back to see if they remain so after.
Even if it’s not the same poster being duplicated each time you still might want to try the steps above. Kind of a collection Plex Dance.
