Pass view as parameter to Button triggering it as a Modal

I'd like to have a custom button struct that receives a view as a parameter that will be shown as modal when the button is clicked. However, the view parameter is always empty, and I can't find the mistake I'm doing. My button struct looks like that:

struct InfoButton<Content:View>: View {
    @State private var showingInfoPage: Bool
    private var infoPage: Content
    init(infoPage: Content, showingInfoPage: Bool) {
        self.infoPage = infoPage
        _showingInfoPage = State(initialValue: showingInfoPage)
    }
    var body: some View {
      return
        Button(action: {
               self.showingInfoPage.toggle()
        }) {
            Image(systemName: "info.circle")
                .resizable()
                .frame(width: 25, height: 25)
                .foregroundColor(.white)
                .padding()
         }.sheet(isPresented: self.$showingInfoPage) {
            self.infoPage
        }.frame(minWidth: 0, maxWidth: .infinity, alignment: .topTrailing)
    }
}

This button is placed in a navigation bar from a template I'm creating for multiple other views. I think the most relevant parts of that template are these:

protocol TrainingView {
    var title: String { get }
    var subheadline: String { get }
    var asAnyView: AnyView { get }
    var hasInfoPage: Bool { get }
    var infoPage: AnyView { get }
}

extension TrainingView where Self: View {
    var asAnyView: AnyView {
        AnyView(self)
    }
    var hasInfoPage: Bool {
        false
    }
    var infoPage: AnyView {
        AnyView(EmptyView())
    }
}
struct TrainingViewTemplate: View {
    @State var showInfoPage: Bool = false
    @State var viewIndex: Int = 0
    var body: some View {
//the views that conform to the template
        let views: [TrainingView] = [
            ExerciseView(),
            TrainingSessionSummaryView()
        ]
        return NavigationView {
                ViewIterator(views, self.$viewIndex) { exerciseView in
                    VStack {
                        VStack {
                            Text(exerciseView.title)
                                .font(.title)
                                .fontWeight(.semibold).zIndex(1)
                            Text(exerciseView.subheadline)
                                .font(.subheadline)
                            Spacer()
                            exerciseView.asAnyView.frame(maxWidth: .infinity, maxHeight: .infinity)
                        }
                    }.navigationBarItems(trailing: (exerciseView.hasInfoPage == true ?  InfoButton(infoPage: exerciseView.infoPage, showingInfoPage: self.showInfoPage) : nil))
                    
                }
            }
}

I debugged to the point, where the navigationBarItems are initialized. At that point, the exercise view has content for "hasInfoPage" and "infoPage" itself.

One exemplary Exercise View has a header like that:

struct ExerciseView: View, TrainingView {
    var title: String = "Strength Session"
    var subheadline: String = "Pushups"
    var numberOfExercise: Int = 1
    @State var ratingValue: Double = 0
    @Environment(\.presentationMode) var presentationMode
    var hasInfoPage: Bool = true
    var infoPage = ExerciseDetailView()

So in this view, the infoPage gets initialized with the ExercieDetailView() which I receive in the TemplateView, but as soon as the InfoButton is clicked, the debugger shows an empty infoPage, even though the "showingInfoPage" variable contains the right value.