I\'m following this SwiftUI tutorial and downloaded the project files.
I built and ran the complete project without any modifications. In the app, if I:
this happens because in the "main" list you toggled to "show only favorites". then you change in the detail the favorites (so it is no favorite landmark anymore) and because in swiftui the source of truth was changed (favorite) this item was removed from the main list and so it cannot be shown in the detail anymore because it is no member of the main list anymore, so the detail view just navigates back and show the favorite items only.