To make the S2 app show that album correctly you need to have an entry in the Album Artist tag. That entry needs to be the same for all the tracks in the album or it will not show as a single album. Sonos has yet to solve the tag reading issue that works OK in S1 but not in S2.
It’s a good idea to use the Album Artist tag which will work better for all software that reads those tags. This is very important for classical music where the Album Artist tags can be vary a lot. After a rip or download purchase of a classical album the Album Artist tag could be anything from Orchestra, conductor, performer or composer. Makes it very difficult to find a particular composer’s work. Yes there may be a Composer search category in most software, but maybe not.
So if it’s a Miles Davis album my Artist & Album Artist tags are both Miles Davis. If it’s Gustav Mahler composition my Artist & Album Artists tags are both Mahler. If it’s a compilation album where there is a mix of artists my Artist tag is the performer and my Album Artist tag is “Various Artists”.