I have, at least twice now, noticed tracks appearing at the top of my "unplayed" tracks list with odd numerical names (e.g. -3510047907225546160.m4p) with little other information besides being AAC protected files and an album cover.
Using the album cover and track length I've so far been able to find a matching track each time that has all the correct meta information and I just delete the weird new track.
I don't have iTunes Match turned on and am not an Apple Music subscriber. I do have Automatic downloads for tracks purchased on other devices turned on. I'd guess there is something going wrong with that setting as these are not recently purchased tracks.
Is this just a bug, or is there a setting I should change to keep these tracks from appearing?