Had similar issues with jellyfin, but I found it had more to do with the file name then contents
Solved a lot of the problem by creating a jellyfin downloader app. It renames the files to make it easier to link them with IMDb. Every time it fails I amend the algorithm so it never happens the same way twice. So far it's 90 to 95% accurate.
The app also works as a torrent engine / transcoder/file manager. It fixes a lot of jellyfins issues and makes acquiring and playing high quality movies almost seamless.
