ViewState does not changing with MapView - swiftui

Question

I'm currently trying to display an Mapview inside a sheet. The weird thing is, that the MapView is shown in the canvas. However in the Simulator it isn't updating the view. Can someone explain to me, what I'm doing wrong?
Here is my MapViewModel
class MapViewModel: ObservableObject {
enum ViewState {
case failed
case loading
case value([Checkpoint])
}
#Published var viewState: ViewState = .loading
#Published var region = MKCoordinateRegion()
func initMap(name: String, address: String) {
self.viewState = .loading
getLocation(from: address) { coordinate in
if let coordinate = coordinate {
let checkpoint = Checkpoint(title: name, coordinate: coordinate)
self.region = MKCoordinateRegion(center: coordinate, span: MKCoordinateSpan(latitudeDelta: 0.1, longitudeDelta: 0.1))
var checkpoints: [Checkpoint] = []
checkpoints.append(checkpoint)
DispatchQueue.main.async {
withAnimation(.easeInOut) {
self.viewState = .value(checkpoints)
print("Done")
}
}
} else {
DispatchQueue.main.async {
self.viewState = .failed
}
}
}
}
func getLocation(from address: String, completion: #escaping (_ location: CLLocationCoordinate2D?)-> Void) {
let geocoder = CLGeocoder()
geocoder.geocodeAddressString(address) { (placemarks, error) in
guard let placemarks = placemarks,
let location = placemarks.first?.location?.coordinate else {
completion(nil)
return
}
completion(location)
}
}
}
And here is my View
struct MapView: View {
#ObservedObject var mapVM = MapViewModel()
var name: String
var address: String
var body: some View {
switch mapVM.viewState {
case .loading:
VStack(alignment: .center) {
ProgressView()
}
.onAppear() {
mapVM.initMap(name: name, address: address)
}
case .value(let checkpoints):
VStack {
Map(coordinateRegion: $mapVM.region, annotationItems: checkpoints) { item in
MapAnnotation(coordinate: item.coordinate) {
VStack(spacing: 0) {
Image(systemName: "mappin.circle.fill")
.renderingMode(.original)
.font(.title)
Text(name)
.font(.caption)
.shadow(color: Color.systemBackground.opacity(0.5), radius: 1)
.frame(minWidth: 0, maxWidth: 150)
}
}
}
}
case .failed:
Text("Failed")
}
}
}
And here is how I implemented the MapView in my MainView
VStack(alignment: .center) {
MapView(name: tickerDetails.name, address: tickerDetails.hqAddress)
.frame(width: UIScreen.main.bounds.width - 30, height: 220)
.border(Color.systemGray4, cornerRadius: 10)
.padding(.leading)
}
Last but not least, here are two Screenshots how its displayed in the canvas and in the simulator:
The data for the preview is coming from an local stored JSON-File. The data for the simulator is fetched from the internet. However the data is loaded correctly, because the print statement is executed in MapViewModel (and the coordinates are also correct). It's just simply not updating the view with the data.
Edit
I implemented the MapView in a "normal" view and it works fine there. It seems to be, that the presented sheet can't work with view states...