I’ve set the “Minimum automatic collection size” to 3 in my library config, and that library is using the Plex Movie Agent (not the legacy one). None of my movies get any collection tags (even after refreshing metadata).
I guess that’s to be expected for the given example.
The Jump Street collection only has 2 items – so even if you have them all in your library, Plex won’t create a collection for them as it’s configured to require at least 3 items
Are all of them matched using the Plex Movie agent? I’ve seen users who switched their library default agent but never refreshed the entire library’s metadata (and as such keeping the existing media matched against whatever legacy agent they had used before).
Sometimes there’s hiccups when somebody creates/deletes collections on The Movie Database and those changes aren’t in line with their “metadata bible”. This can cause collections to be temporarily removed or missing from Plex’ synced database even if it’s still showing online. Then again… Star Wars seems to be an instance that is unlikely to be deleted by a misled community member