Make sure you follow Plex naming & organization requirements. Plex is especially picky with TV shows.
In Plex Web, filter the view to search for duplicates (view the desired library, click on “All” and choose “Duplicates.”). Make sure Plex has not inadvertently matched the new media to an existing movie/show. Filtering for Unmatched may provide useful information as well.
Perform the Plex Dance when moving/re-naming/deleting/etc media. This clears out any incorrect information from the Plex database.
Check for database corruption.
