I'm using iTunes 12 and change.
I've been transferring a bunch of older CDs into my iTunes so i can put the CDs in storage and I'm finding it's splitting individual albums up with some frequency -- like maybe one in three has an issue.
So far, the fix has been the same -- highlight the songs and place a random letter in "album artist"
BTW, I found a version of this fix on You Tube, only the guy says to insert a blank space in the "album artist: field. That has failed to work for me, but a random letter works just about every time.
It would be so much easier if we could just drag songs where we want them in iTunes. Some of my older CDs are long out of print and came with sometimes a significant number of extra tracks (like Rykodisc CDs) that iTunes doesn't even recognize.
I'm spending a lot of time not just consolidating the tunes into their proper albums, but sometimes I even have to manually type in the track names and find artwork for the album.