The problem can be reproduced with the template document based SwiftUI iOS application.

I have the same problem. The document group closure which returns the ContentView seems never to be executed. This is a problem for Mac Catalyst and for directly executed iOS applications on Apple Silicon macs (Designed for iPad).

In my case I found an easy solution: Xcode > Settings... > General: Deactivate: Show live issues All error appeared which before were gone.