From Roon 1.7 (Build 521) is Live!:
Finally, this release fixes a bug preventing our compilation sorting options from working properly. For example, say you have the compilation “ Now That’s What I Call Music ” – the “ Use Album Title ” option means this album will be sorted to
Nin the album browser. Alternatively, the “ Use Various Artists ” option means that all compilations will sort toV.
You can change it in Settings|General; last entry in the list (you may have to scroll down).