why ToolbarItemGroup appears only on the first tab?

// just check the below code. it's about simplest possible to // looks the same with simulator and real device with iOS 17.1+

import SwiftUI

struct MainTabView: View {
    @FocusState private var focusedField: Bool
    
    var body: some View {
        TabView {
            TextField("test 1", text: .constant("test 1"))
                .focused($focusedField)
                .tabItem {
                    Label("tab 1", systemImage: "number")
                }
                .toolbar {
                    ToolbarItemGroup(placement: .keyboard) {
                        Button("Done") { focusedField = false }
                    }
                }
            
            Text("test 2")
                .tabItem {
                    Label("Home", systemImage: "house")
                }
            
            TextField("test 3", text: .constant("test 3"))
                .focused($focusedField)
                .tabItem {
                    Label("tab 3", systemImage: "number")
                }
                .toolbar {
                    ToolbarItemGroup(placement: .keyboard) {
                        Button("Done") { focusedField = false }
                    }
                }
        }
        .tint(.primary)
    }
}

@main
struct MainApp: App {
    var body: some Scene {
        WindowGroup {
            MainTabView()
        }
    }
}