I don't pay for Apple Music so I don't use it, but it seems you erased all files and links in your playlist for Apple Music.
I would take a screenshot of the playlist then delete all of it and re-add them. I would even delete your current music inside the app as well to cover all folder bases.
If that doesn't work then wait for Saurik to complete the restore to current firmware tweak (forgot the name atm), I believe is still in beta but should be finished soon. So you can restore to your current firmware, use older backup than when it happened then jailbreak it again.