Matching for multi-disc albums

[kavermeer]

Thanks for the quick response! There are certainly different artist tags, although they all share one artist (it's a set of all EMI Oistrakh recordings). I am surprised that most of the discs are matched, even though they contain different artist tags as well.

I added the AlbumArtist tag, which resulted in all discs being combined. But, I now no longer see the '>> Disc x' subdivision in my CP (BubbleUPnP). Just to be sure, I removed the AlbumArtist tags, which made the disc-divisions visible again.

Any idea what's causing this behavior?