Cannot add imported music to a playlist
I have an Apple Music subscription, and I would like to add mp3's to my Apple Music library, in which I usually do through iTunes. But now I can no longer add my imported music to any of my playlists. I used to be able to, but I can't anymore.
When I try to add them to a playlist, they show up in the playlist for about 2 minutes, and then disappear when I check the playlist again.