How to prevent the background color from going beyond the safe area when rotating the simulator

I need to use some "uikit view controller" in my swiftui app. I have encapsulate the vc in a representable view. It works well. However, the background color will extend outside of safe area when I rotate the simulator from portrait to landscape and back to portrait.

I want the background color always to stay inside safe area. I prototype a sample code to illustrate the issue.

struct ContentView: View {
    var body: some View {
        ZStack{
            Color.gray
            CustomRepresentation()
        }
    }
}
struct CustomRepresentation: UIViewControllerRepresentable{
    func makeUIViewController(context: Context) -> some UIViewController {
        return UIViewController()
    }
    func updateUIViewController(_ uiViewController: UIViewControllerType, context: Context) {
        
    }
}

If I comment the CustomRepresentation(), the gray color will stay inside the safe area all the time during rotating. So I realize the key point is CustomRepresentation(). But I don't know how to fix it.