Ok great.
- Stop PMS
- Go into the Library/Application Support/Plex Media Server/Plug-in Support/Caches directory.
- Delete everything you see there.
- Start PMS.
Now, before rescanning, Did you attempt to rename the media after PMS scanned it the first time?
If so, you must first purge the old data.
- Move the item out,
- Scan files
- Empty Trash
- Clean Bundles
- Move the media item back in
- Scan again.
With all your media ready to be scanned. “Refresh all metadata” for the library section which needs it.