You’re close. Try one of the two below. The first matched immediately on my server.
You may need to Plex Dance the movie after renaming.
Also, Plex may be picking up bad embedded metadata, which will throw off matching. If you do not need Plex to read embedded metadata, make sure the capability is disabled.
Edit the library → Advanced → uncheck “Prefer Local Metadata” and save changes.
/Movies <-- folder added to Movie library
/The Boogeyman (2023) <-- year in parenthesis
/The Boogeyman (2023).mp4
or
/Movies <-- folder added to movie library
/The Boogeyman (2023) {imdb-tt3427252} <-- dash, not space, after imdb
/The Boogeyman (2023) {imdb-tt3427252}.mp4
