Some combination of an active search query, active filter, and the only highest version option being enabled results in it sometimes not being respected.
https://mcresourcepile.github.io/maps/pgm?query=frac&filters=4teams&match=all&invert=false&highest_version=true
If you untoggle 4teams then duplicate versions of the map will appear. Toggling it again hides them correctly.
From what I can tell it has something to do with the query search input.
Maybe that event listener just needs to call a filter refresh?