SwiftUI ToolbarItemGroup(placement: .principal) makes dynamic content unresponsive

I have a SwiftUI view like follows:

struct ContentView: View {
    
    @State private var showButton2 = false
    
    var body: some View {
        NavigationView {
            Button("show button2") {
                showButton2.toggle()
            }
            .toolbar {
                ToolbarItemGroup(placement: .principal) {
                    HStack {
                        Button("button1") {
                            print("button1 pressed")
                        }
                        
                        if showButton2 {
                            Button("button2") {
                                print("button2 pressed")
                            }
                        }
                    }
                }
            }
        }
    }
}

With this I want to achieve dynamic .toolbar buttons.

Button1 works perfectly before showing button2. After button2 is presented, button1 doesn't respond well to touches anymore. Button2 on the other hand works fine.

If I change the placement to anything else (e.g. navigationBarLeading) the code works as expected and button1 is responsive.

Does anyone know why button1 isn't responding well to touches anymore and how to fix that?