I've noticed since the update that, when I sort by artist within "Songs" or in a playlist, the tracks are arranged in a random order - tracks are intermingled between the albums they come from, instead of being grouped with tracks from the same album. At first I thought that the tracks were possibly being arranged by the order in which I'd saved them to Your Music, but this did not prove to be the case.
This also carries over into playlists when trying to sort the playlist by artist. I've attached 2 pictures demonstrating the problem.
I personally always used "Songs" to find tracks/albums that I'd saved by Artists, given how clunky the "Artists" section of the desktop app was (giant thumbnails, no ability to jump to an artist by typing the name out? Seriously?), but this mis-ordering is driving me nuts. If it's a bug, please fix it. If it's intentional, please cancel my Premium subscription.
This is a known issue and will be fixed in a future update.