Just to piggyback on this, I have had the same problem that Groaninjock describes in the past, which I only fixed by doing the Plex Dance with the files.
In my case, as in the OPs, my albums were all correctly tagged and stored in separate folders. I’ve had this happen a variety of times, always with an artist which exists in my library (say, Wes Montgomery) and another “artist” such as Wes Montgomery & Jimmy Smith.
Plex likes to “assume” that the albums that are just Wes Montgomery are actually Wes Montgomery & Jimmy Smith, even though they are in a Wes Montgomery folder with all the tags 100% correct. And, when I’ve changed these tags/metadata in Plex BACK to just, say, Wes Montgomery, after a few minutes Plex changes them BACK to Wes Montgomery & Jimmy Smith, even though there is absolutely no reason for Plex to do that.
The original file structure I saw from the OP, which was in the Plexamp reddit (linked to above), shows a clearly separate file structure. I’ve posted about this many times, and it’s never really been addressed.
So really, all I’m saying is that the OP is not crazy, and this is behavior I’ve seen before on more than one occasion.
