Server Version#: 1.31.1.2262-74fdc6b7
Player Version#: Plex for MacOS
There are a few albums in my collection where the metadata is the same but there album is split up where a couple tracks are in their own album. I’ve triple check the metadata.
Screenshots from an example. The “Album” ID3 tag is set to “10,000 Days” for all tracks.
I’ve found that Plex will do this to an existing album if I rename the file for any of the tracks. I mentioned it to them last summer. As you found, removing the album and restoring it (the infamous “Plex Dance”) corrects it. They finally made some changes a couple years ago that fixed most of the situations that required the Plex Dance. This is one of the remaining issues. It is most certainly a bug.
I also found that I can select the two albums and choose “Merge” which is a lot easier, assuming it fixes it a similar way that won’t just get split again.
I’d love to find a way to find these albums that have the same exact name under the same artists but are in different albums.