Selection in NavigationLink is not working - swiftui

Question

I have the following code for my iPad app:
struct ContentView: View {
#State var selectionIndex: Int? = nil
var body: some View {
NavigationView {
VStack {
ForEach(0..<5) { tag in
NavigationLink("Link \(tag)", destination: DetailView(name: "View \(tag)"), tag: tag, selection: self.$selectionIndex)
.foregroundColor((self.selectionIndex ?? 0) == tag ? Color.red : Color.black)
}
}
}
}
}
struct DetailView: View {
var name: String
var body: some View {
Text(self.name)
}
}
Pressing the links works perfectly and also it changes the DetailView. I try to highlight the selected button, therefore I save the selectionIndex.
Unfortunately the selectionIndex sometimes resets to 0. What am I doing wrong?
EDIT
Wrapping the NavigationLink into a List shows the problematic better, as the List has it's own selection (this selection stays, but my own var selectionIndex resets).
NavigationView {
List {
ForEach(0..<5) { tag in
NavigationLink("Link \(tag)", destination: DetailView(name: "View \(tag)"), tag: tag, selection: self.$selectionIndex)
.foregroundColor((self.selectionIndex ?? 0) == tag ? Color.red : Color.black)
}
}
}
See this screen:

Answer 1

Well, this of course looks like a bug, but they do what they documented - show destination of selected tag, no more. Anyway, probably worth submitting feedback.
Here is a working workaround. Tested with Xcode 11.4.
#State var selectionIndex: Int? = nil
#State var highlighted: Int? = nil // << explicit !!
var body: some View {
NavigationView {
VStack {
ForEach(0..<5) { tag in
NavigationLink("Link \(tag)", destination:
PadDetailView(name: "View \(tag)").onAppear { self.highlighted = tag },
tag: tag, selection: self.$selectionIndex)
.foregroundColor(self.highlighted == tag ? Color.red : Color.black)
}
}
}
}