Music pauses by itself

My Air Pods Max play fine with my iPad (if I’m not doing anything else on it), but if I pick up the iPad and start to read a book or surf the web, the music from pandora or my own music library repeatedly pauses by itself without any action on my part. The music won’t resume unless I go to the app I’m using and tap the play button. I can’t restart it by using the Digital Crown. I’m up-to-date on my software and I’ve tried forgetting all my Bluetooth devices and re-pairing them but it keeps happening.