I'm doing tests for a similar situation, although I only need to play a short audio instead of a full song or playlist.
I finally was able to make It work by awaiting the audio to be finished before returning in the perform() method.
It looks like it's not your case but it might give you at least an idea.
juequinterore
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution