Nice fix for this problem. The purpose of this example was getting the .onChange to work correctly to call a function for selecting multiple values. Thanks for the help.

The complete MapView.swift with all of the changes noted above, which are the only changes to the downloaded project identified above: import SwiftUI import MapKit struct MapView: View {     var coordinate: CLLocationCoordinate2D     @State private var region = MKCoordinateRegion()     struct Place: Identifiable {         let id = UUID()         let name: String         let coordinate: CLLocationCoordinate2D     }     var annotations = [         Place(name: "Xyz", coordinate: CLLocationCoordinate2D(latitude: coordinate.latitude, longitude: coordinate.longitude))     ]     var body: some View {         Map(coordinateRegion: $region, annotationItems: annotations) {             MapPin(coordinate: $0.coordinate)         }         .onAppear {             setRegion(coordinate)         }     }     private func setRegion(_ coordinate: CLLocationCoordinate2D) {         region = MKCoordinateRegion(             center: coordinate,             span: MKCoordinateSpan(latitudeDelta: 0.2, longitudeDelta: 0.2)         )     } } struct MapView_Previews: PreviewProvider {     static var previews: some View {         MapView(coordinate: CLLocationCoordinate2D(latitude: 34.011_286, longitude: -116.166_868))     } }

All of the code is in the SwiftUI tutorial at the URL provided above. Start with the BuildingListsAndNavigation.xcodeproj in the Complete folder of the downloaded project. I have just now repeated the changes shown above starting with a new download, with the same results. Note that the addition goes before the View, which is completely replaced.