Odd SwiftUI Bug on macOS

This is an odd bug on macOS:

1. Make the main content view a NavigationSplitView:

struct ContentView: View {
    var body: some View {
        NavigationSplitView {
            Spacer()
        } content: {
            Spacer()
        } detail: {
            Spacer()
        }
    }
}

2. Launch the app.

3. Observe that there is an “Enter Full Screen” menu item in the “View” menu.

4. Go to the Finder.

5. Go back to the app. Observe that the “Enter Full Screen” menu item in the “View” menu is gone.

Filed as FB12064842.