on Xcode Version 15.0 (15A240d): focusState not work in navigationStack?

its not work on Xcode Version 15.0 (15A240d): focusState is always nil when use focusState in navigationStack. It not work in onAppear && setNextFocus on real device. here is the code:

enum NameField {
    case focus1
    case focus2
    case focus3
}

struct ContentView: View {
    @State private var text1 = ""
    @State private var text2 = ""
    @State private var text3 = ""

    @FocusState private var nameField: NameField?
    var body: some View {
        NavigationStack {
            VStack {
                TextField("Field One", text: $text1)
                    .focused($nameField, equals: .focus1)
                TextField("Field Two", text: $text2)
                    .focused($nameField, equals: .focus2)
                TextField("Field Three", text: $text3)
                    .focused($nameField, equals: .focus3)
            }
            .textFieldStyle(.roundedBorder)
            .padding(.horizontal)
            .onAppear {
                  self.nameField = .focus1
            }
            .toolbar {
                ToolbarItemGroup(placement: .keyboard){
                    Spacer()

                    Button{
                        setNextFocus()
                    } label: {
                        HStack {
                            Text("Next")
                            Image(systemName: "rectangle.trailinghalf.inset.filled.arrow.trailing")
                        }
                        .foregroundColor(.orange)
                    }
                }
            }
        }
    }

    func setNextFocus() {
        if nameField == .focus1 {
            nameField = .focus2
        } else if nameField == .focus2 {
            nameField = .focus3
        } else if nameField == .focus3 {
            nameField = .focus1
        } else {
            // choose what you want to do
        }
    }
}