When I open the IPP the music stops and nothing is playing (music) nor is anything open in task.I had this on iOS 14.4 sometimes when taking out my AirPods and putting them away. It would trigger the iPad start playing some random music of my library. Haven't seen it on 14.5 beta 1 so far.
What do you see when you open the Music app? Does it play there? Then you should see where it comes from.
By the icon it looks like Apple Music. However if I click that app, it takes me into the new user screen.
baffling.