Audio from app stops when iPhone locks after iOS 17.6.1 update

I normally listen to the app with the screen locked with on the treadmill.

Since the update, the audio stops when the screen locks but the audio time keeps moving. When I open the screen, the audio can be heard but it is now at a different spot. If I switch apps, the audio stops as well. Never had this problem. Not sure if that makes sense or if it’s happening to anyone else.

It’s frustrating. I shouldn’t have to keep the screen unlocked to listen and waste so much battery.