Map zoom in

Any help would be appreciated, thanks
My first click on a list item to zoom in to my map area works fine, however when i click to zoom a second time it does not zoom.

func mapView(_ myMapView: MKMapView, didAdd views: [MKAnnotationView]) {

    if let annotationView = views.first {
        if let annotation = annotationView.annotation {
            if annotation is MKUserLocation {
                let region = MKCoordinateRegion(center: annotation.coordinate, latitudinalMeters: 3500, longitudinalMeters: 3500)
                myMapView.setRegion(region, animated: true)
            }
        }
    }
    
}