iOS15 NavigationView 在将应用程序置于后台并将其恢复后丢失了 state

Question

在应用程序中，如果我按照 MainView->Tab1->Link1->Sub Link1 的导航，将应用程序置于后台，然后将其带回，然后再次显示回 Tab1，有谁知道为什么 NavigationView 不能保留最后一个看法？ 它在 iOS 14.7 中运行良好

struct LocalNotificationDemoView: View {
    @StateObject var localNotification = LocalNotification()
    @ObservedObject var notificationCenter: NotificationCenter
    var body: some View {
        NavigationView {
            VStack {
                MainView()
            }
        }
        .navigationViewStyle(.stack)
    }
}

struct MainView: View {
    var body: some View {
        TabView {
            Tab1()
                .tabItem {
                    Text("Tab1")
                }
            
            Tab2()
                .tabItem {
                    Text("Tab2")
                }
        }
    }
}

struct Tab1: View {
    @State var selection: Int? = nil
    var body: some View {
        NavigationLink(destination: View1(), tag: 1, selection: $selection) {
            Text("Link 1")
        }
    }
}

struct Tab2: View {
    @State var selection: Int? = nil
    var body: some View {
        NavigationLink(destination: Text("Link 2").navigationTitle("").navigationBarHidden(true), tag: 1, selection: $selection) {
            Text("Link 2")
                .onAppear {
                    print("Link2 shows")
                    Thread.callStackSymbols.forEach{print($0)}
                }
        }
    }
}

struct View1: View {
    @State var selection: Int? = nil
    var body: some View {
        NavigationLink(destination: Text("Sub Link 1"), tag: 1, selection: $selection) {
            Text("Sub Link 1")
        }
    }
}