Map repositions itself after panning

It seems you end up adding annotations a lot of times by doing it in

func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView {

That should probably be done in viewDidLoad.

Did you look at this tutorial to see how to implement all this ?

h ttps://www.raywenderlich.com/548-mapkit-tutorial-getting-started

But the annotations dont show up.

It adds annotations inside the visMapRect and then moves around to a different location without showing any annotations over there (they only load when i move the map a bit).

So the map adds annotations inside the Viewdid Load and just defines its properties and icon inside this mapView function

I tried around a little bit changing different types and realised that there really seems to be a problem with the icons.

when i set everything to MKMarkerAnnotations everything is fine. When i only change annotationView to MKMarkerAnnotationView it displays normal marker annotations with the clusters having customised icons and it starts laggin a bit. And when i leave everything as MKAnnotation so the annotations and clusters both have customised icons the problem (map jumping around) occurs.

Could there be a problem with handling different image formats?

You are not dequeuing annotations, but recreate them each time.

I think that could be the problem.

See here a code sample for MKMarkerAnnotations:

   func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {

        var annotationView = MKMarkerAnnotationView()
        guard let annotation = annotation as? PizzaAnnotation else {return nil}

        if let dequeuedView = mapView.dequeueReusableAnnotationView(withIdentifier: "identifier") as? MKMarkerAnnotationView {
            annotationView = dequeuedView
        } else{
            annotationView = MKMarkerAnnotationView(annotation: annotation, reuseIdentifier: "identifier")
        }
        annotationView.markerTintColor = color
        annotationView.glyphImage = UIImage(named: "pizza")
        annotationView.glyphTintColor = .yellow
        annotationView.clusteringIdentifier = "identifier"
        return annotationView
    }

from h ttps://makeapppie.com/2018/02/20/use-markers-instead-of-pins-for-map-annotations/

still the same problem occuring

another thing i just realised is that sometimes the map automatically selects annotations (opening their callout)

maybe the map selects annotations which are somwhere else, so it zooms to their location?!

Also: when the map has moved itself to a different location, no annotations are displayed, so it doesnt realise that the region has changed (otherwise it would add annotations as soon as the panning has stopped)

Could you post your new code, after the modifications ?

Sure:

func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView? {
     var annotationView MKAnnotationView()
     guard let annot = annotation as? customAnnotation else {return nil}

     if let dequeuedView  = mapView.dequeueReusableAnnotationView(withIdentifier: "identifier") {
          annotationView = dequeuedView
     }
     else {
          annotationView = MKAnnotationView(annotation: annot, reuseIdentifier: "identifier")
     }
     
     annotationView.image = UIImage(named: "pin")
     annotationView.canShowCallout = true
     annotationView.clusteringIdentifier = "identifier"

     return annotationView
}

i again added some button after the clusteringIdentifier but i dont think they are the problem