Plex poster blank on duplicate movies?

It sure isn’t helping matters.

Nope - like this:

The Movie (2020) [2160p]/
...The Movie (2020) [2160p].xxx

...The Movie (2020) [1080p]/
......The Movie (2020) [1080p]./xxx

Two ‘unique’ folders.

First do this:

(in case any of those files are MP4/M4V with bogus embedded Title Fields)

Remove ALL those movies/versions
fix the names and structures while doing this:

That will completely ‘Re-Do’ the bundles for this thing - starting all over - hopefully, with all the right stuff this time.