I’m looking for a solution to this as well. All my Various Artists albums suddenly all belong to Duke Ellington.
I took one album out, checked the metadata and file structure, did the Plex Dance, put the album back in and instead of one album, it wanted to make each song its own album by the song’s artist instead of the Album Artist which I have set as Various Artists. I did a merge and then manually edited that album artist to Various Artists.
I really don’t want to have to manually edit each of the albums when I’ve worked so hard to get the metadata, file naming, and file structure right in the first place AND confirm each album lands in the library correctly when first added.
My library is also set to use the Plex Music scanner and agent and prefer local metadata is checked. I’m going to keep searching, but so far I’m not finding any solution to fix this when the file structure, file naming, and metadata is already the way Plex wants it.