Disabling "Enable Results" fixed this for me :)

I've filed a bug through Feedback Assistant for this issue (with an attached minimal reproducible example), the feedback ID is FB9067573

@rick21 Can you explain what you mean by "moving the view to a separate file in Sources"? This bug is currently giving me massive trouble, and Command+0 does nothing. @jasonag Swift Playgrounds on Mac is where this bug occurs...

I am pretty sure it just has to work on 14.4.2, not that YOU have to be on 14.4.2. A playground made on macOS playgrounds works on iPadOS playgrounds - and app version is independent from OS version, so I doubt it really matters.