The solution is to do exactly what the exception message tells you:
Caused by: org.hibernate.ObjectDeletedException: deleted object would be re-saved by cascade (remove deleted object from associations)
Remove the deleted object from an associations (sets, lists, or maps) that it is in. In particular, i suspect, from
PlayList.PlaylistadMaps. It’s not enough to just delete the object, you have to remove it from any cascading collections which refer to it.
In fact, since your collection has
orphanRemoval = true, you don’t need to delete it explicitly. You just need to remove it from the set.