Using XCode 12.5.1, Big Sure, iMac Pro.

My iOS app has a home page NavigationView which lists various entirely different pages. I want to be able to use the home NavigationView to go directly to a page, and I want to be able to swipe between the pages. I have it more or less working: this is a simplified version of the structure which shows what I'm trying to do:

struct Tab: Hashable {
    let name: String
    let id: Int
}

struct ContentView: View {

    let tabs: [Tab] = [Tab(name: "first", id: 1), Tab(name: "second", id: 2), Tab(name: "third", id: 3)]

    var body: some View {
        NavigationView {
            Form {
                List (tabs, id: \.self) { tab in
                    NavigationLink(destination: Dispatcher(which: tab.id)) {
                        VStack (alignment: .leading) {
                            Text(tab.name).font(.headline).bold()
                        }
                    }
                }
            }.navigationTitle("test")
        }
    }
}

struct Dispatcher: View {
    var which: Int
    @State private var tab = 0

    var body: some View {
        TabView(selection: $tab) {
            Text("first page").tag(1)
            Text("second page").tag(2)
            Text("third page").tag(3)
        }
        .tabViewStyle(PageTabViewStyle(indexDisplayMode: .never))
        .onAppear(perform: { tab = which })

    }
}

On a phone or phone simulator, it works fine. On an iPad, thought, I have two problems:

1. In the iPad Pro 12.9 inch simulator, whichever item I select in the NavigationView takes me only to the first page. On an actual iPad, though, it works fine. I suspect a simulator bug but I'd be interested if anyone doesn't have this issue.

2. On the actual iPad Pro, I tap, say, "second" and it duly brings up the second page. I swipe left and the third page appears. However, "second" is still selected in the NavigationView list, so tapping it does nothing. How can I change the selection in the NavigationView list to match the actual displayed page?

Thanks!

Jeremy

I'm wrong. I have updated my iPad to iOS 14.6 and it now behaves exactly as the simulator. Whatever i select in the NavigationView, it goes only to the first page. I can swipe to other pages but I can't go to them directly.

I don't understand!

If I put

print(which, tab)

into the onAppear closure, before and after the assignment, I can see that the value of tab is changed appropriately. It's just that on the iPad, the TabView doesn't react, as it does on the iPhone.