Is this an iOS8 specific issue you're seeing? Could be a bug if so.
Otherwise, general information: Tags and sorting. If it's a "Various Artists" release, then make sure all the tracks are tagged with compilation flag set to YES - if everything else is correct, such as album name, and year, then that should make sure everything is grouped together if all album tracks are by different artists. It will sort under Various Artists in such a case.
The alternative, used for non-VA albums that have guest tracks, is to set ALBUM ARTIST to the primary artist and then you can have compilation set to NO and it will still group when track artists differ (album name the same).
All my music is precisely tagged for maximum compatibility with iTunes, iOS and Slim Server (aka Squeezebox Server aka Logitech Media Server)
No it did it on my five for a bit before I got this one. It's strange because it's doing it on albums I've bought straight through the digital iTunes and not ones I ripped from CDs.