That depends on how broken the database is I would assume. Theoretically they can fix this (or reset the database so that you can at least start anew), but they need to know about this. I've seen reports from two years ago where this happened on other occasions, so this might not be fixed in the near future.

This does the same thing in SwiftUI. You'd need to test if it works on visionOS, though. .toolbarBackgroundVisibility(.hidden, for: .navigationBar)

Except it does not save space. When you drill into a UINavigationController stack, and the title of the controller is different from the tab's title, it will display a double-height nav bar and it looks ugly as hell.