If I enter the Minecraft app, then leave it, then enter it again, the sound won't play, but when I go to audio settings it shows the sound at 100%. However, if I double click the home button and swipe away Minecraft, then open the app, the sound will play, but as soon as I leave again (and don't swipe the app away), when I reopen the app, there's no sound. 

I haven't experienced this problem before updating my iPhone to iOS 14.