Can't lock Apple Music app to Recent Apps on Samsung devices running Android 12

I'm using Apple Music app on Samsung Galaxy S10e, Android 12. I used to be able to lock it in Recents so it wouldn't close with Close All. Now when I tap "Lock this app," nothing happens. No other apps were affected. Uninstalling/reinstalling the app doesn't work. Rolling back to previous app versions doesn't work. Apple has no idea what I'm talking about when I try to get support.