A better quality, another edition, or a smaller file: pick the release yourself.
In Broadcast: the film’s page, More, then (for administrators) Choose a release or Manage files. The Options key opens More too.
In Classic or Neu: the film’s page, Manage.
Type its name and pick it from your library.
You type a name and pick it from the list.
This is for a film you already have. Press Back and pick another.
Its page.
Lists every release your indexers have for this film, best match first, with its quality and size and why Usherr would skip one. Pick the one you want: Usherr asks before replacing your file, and swaps it in only once the new one is complete. The old one goes to the recycle bin. (Each look counts against your indexers’ daily limits.)
Moved the film to a lower quality profile, 4K to 1080p say? Replace with a smaller version, next to Choose a release, finds a smaller copy and only then removes the big file.
Automatic searches still upgrade by themselves, up to what the film’s quality profile allows.