If a TV Show season or Movie is moved from one disk location to another, it is completely removed from the library once the empty season folder in the old location is removed.
The server is configured to automatically scan for changes and clear the trash after library updates.
Examle:
The Section "TV Shows" has to locations:
- /Volumes/A/Media/TV Shows
- /Volumes/B/Media/TV Shows
Move /Volumes/A/Media/TV Shows/Foo/Season 1 to /Volumes/B/Media/TV Shows/Foo/Season 1.
- First Plex will detect the files in the new location as they are being added during the move, so they will all show up as duplicate (expected).
- After the move is complete, all the source files are removed, Plex removed the duplicates (expected).
- After all the files have been remove in the source location, the empty folders for Season 1 and Foo are removed.
- Plex removes the whole Season 1 from the Library, to get it back you have to rescan the TV Shows section. (BUG)
This is really annoying if you regularly move seasons from the local disk to an external drive.
The bug exists for a really long time, including the latest 1.9.5 betas and happens at least on macOS when moving seasons or shows using the Finder.