I think the example app have a weird bug introduced by newest iOS version(14.5): Navigation Link results in Unable … | Apple Developer Forums
When I tap on a row on FlightStatusBoard, FlightDetails View will open then immediately close, which should be a bug. Running the provided final project has the same behaviour.
Moreover, I tried to run Chapter 14’s final project, the above problem didn’t occur, but there’s a console message “Unable to present. Please file a bug.”.
Adding following in the beginning of WelcomeView’s VStack somehow did solve this weird problem:
NavigationLink(destination: EmptyView()) { EmptyView() }