Music app on iPad can’t add tracks to any playlists
I’m using the Music app on iPad (air 2, 64GB, WiFi), I’ve got several playlists that I synchronise to my iPhone 5, which I have built up over the last couple of years, but I’ve found in the last week that I can’t add any tracks to any playlists, including new, empty, playlists, and existing ones.
When attempting to add a track to a playlist, Music reports that it has been correctly added, but when viewing the playlist (on either device) the track doesn’t appear.
Apple music tracks and my personal uploads all playback fine, but attempts to add to playlists always fail (although removing existing tracks from playlists appears to work).
I’m not really sure how to attempt to debug this as it reports success and doesn’t give any error notifications - does anyone have suggestions?