Hello!
I recently added all 13 seasons of Columbo to my Plex Server. Each season is in it’s own folder in the Columbo folder and all have the exact same naming convention. For some reason, Plex can’t see Season 5-9 and I can’t figure out why.
Mind sharing your specific naming schema?
In case the files of seasons 5-9 are mp4/m4v/mov containers… do they contain any “conflicting” metadata that could throw Plex off?
Have you checked those episode files for embedded titles?
Assuming the files are actually in your library… you can switch the library view to display episodes and filter it for Duplicates to identify where they might have ended up.