You and 1.9 million Plex Users - unfortunately… better do the LMA Hack. After that Plex will do what Users find a sane approach to bogus embedded metadata in MP4/M4V files. <—not preferring it over a file name <— a good file name, we hope.
I suggest you Plex Dance all files that are misbehaving - after the LMA Hack - and after you check TMDB to see if you have the names right.
If every AVI file on planet earth exploded - it would be hilarious and not effect me in the slightest. I also won’t feel bad if one never plays or behaves for you, but I am under the impression the ONLY files Plex can read metadata in is an MP4/M4V.
More investigation is warranted, but really I don’t care either way. I did the LMA Hack and removed all the metadata and have nothing, but MKV files for the last few years, so I’m not worried. We have anti-metadata security many layers deep and between FileBot and myself - we’re so close to 100% accuracy Bill Shatner called me to do a segment on “The UnXPlained” …lol
