Duplicate movie (instead of versions), with collection to add insult to injury

[Iskelderon]

Did you enable this setting in your library settings?

I don't even have that option there.
It jumps straight from "Prefer embedded titles over filenames and "Enable real time monitoring" to the  metadata source lists for TV shows and movies and then to "Automatically refresh metadata from the internet" after the metadata download sections.
I vaguely remember removing a plugin that led to the program pumping out duplicate collections with rather similar names, but that was a while ago.

From a layman's perspective: The problem here seems to stem from it initially pibling up two files in the movie's folder, generating two entries, which probably triggers the collection generation, but when the "Merge All Movies" task comes around, it now merges the versions, but doesn't flatten the display of the movie as one item again and remove the single-movie collection container that's now there.

The weird thing is that it works for other movies where I have multiple versions (though I need to use the square brackets so it reliably sees the versions as intended), but in this specific case, the program just doesn't get it.