Disable Audio on iPad Lock Screen

Hello! I'm looking for a way to disable the audio on an iPad's lock screen. I'm having an issue where a student is watching a YouTube video with a timer set on a break, timer goes off, iPad gets locked, and the audio from the video that is able to still be played from the built-in player on the lock screen causes classroom problems. I've tried two Config Profiles that didn't work--one that restricts the Apple Music app, one that restricts AirPlay receiving--but I'm not even sure if doing this is possible. Would love to hear any solutions or insights anyone might have! Thank you.