Filter your library at the top left for duplicates
All extra info in a movie name should be in square brackets. That tells Plex to ignore it when it comes to matching.
RRR (2022) [2160p Atmos].mkv
Guardians of the Galaxy Holiday Special (2022) [UHD 2160p Atmos].mkv
Plex may use that information thinking that it’s actually part of the movie name and it may get matched to some other movie that gets hidden in your library under another name too
Plex dance the missing movies adding the square brackets and see if they show up
