I bought a copy of AC-DC’s Who made Who from the iTunes music store. It will not recognize it as an “album” by AC-DC, but as a Soundtrack. I have done the Plex dance, and I have used MP3 tag to tag every file with MusicBrainz metadata. Still, it looks like this. Note: the compilation tag is not checked.
That’s because it is a soundtrack album: https://en.wikipedia.org/wiki/Who_Made_Who
That flag does not affect Plex.
You can only change the classification if you have “prefer local metatags” enabled.
Then you need to insert “RELEASETYPE” tags into all tracks of this album and fill them with album;album.
Depending on the file format of your tracks, the name of the tag can also be just “Release Type”. See https://forums.plex.tv/t/metadata-to-list-album-as-live-album/933087/2
