InfoWindowClicked on custom pin does not work on IOS

Hello guys, im stuck with a problem with the InfoWindowClicked event on Xamarin.Forms.Maps.
The event fires correctly on Android but don't fire on IOS (testing in simulator).
I made a simple CustomRenderer in order to change the pin icon, these are my files:

public class CustomMap : Map
{
public List CustomPins { get; set; }
}

public class DataPin : Pin
{
public string Icon { get; set; }
}

This is my custom renderer on IOS (pretty much the same of the doc):

public class CustomMapRenderer : MapRenderer
{

    List<DataPin> customPins;

    protected override void OnElementChanged(ElementChangedEventArgs<View> e)
    {
        base.OnElementChanged(e);

        if (e.NewElement != null)
        {
            var formsMap = (CustomMap)e.NewElement;
            var nativeMap = Control as MKMapView;
            customPins = formsMap.CustomPins;

            nativeMap.GetViewForAnnotation = GetViewForAnnotation;
        }
    }

    protected override MKAnnotationView GetViewForAnnotation(MKMapView mapView, IMKAnnotation annotation)
    {
        if (annotation is MKUserLocation)
            return null;

        var customPin = GetCustomPin(annotation as MKPointAnnotation);
        if (customPin == null)
        {
            return null;
        }

        MKAnnotationView annotationView = mapView.DequeueReusableAnnotation(customPin.Label);
        if (annotationView == null)
        {
            annotationView = new MKAnnotationView(annotation, customPin.Label)
            {
                Image = UIImage.FromFile(customPin.Icon),
                CalloutOffset = new CGPoint(0, 0)
            };
        }
        annotationView.CanShowCallout = true;

        return annotationView;
    }

    DataPin GetCustomPin(MKPointAnnotation pin)
    {
        if(customPins != null)
        {
            var position = new Position(pin.Coordinate.Latitude, pin.Coordinate.Longitude);
            foreach (var customPin in customPins)
            {
                if (customPin.Position == position)
                {
                    return customPin;
                }
            }
        }
        return null;
    }
}

Here is the sample code where i add a pin with the InfoWindowClicked event (i removed some parts):

myfunc()
{
CustomMap map = new CustomMap()
{
IsShowingUser = true,
MapType = MapType.Street,
};
map.CustomPins = new List();

DataPin pin = new DataPin
            {
                Label = stop.Nome.Replace("_", " ").ToUpper(),
                Type = PinType.Place,
                Position = new Position(stop.Coordy, stop.CoordX),
                Icon = "stop_pin.png"
            };
            pin.InfoWindowClicked += pinClickedEventHandler;
            map.Pins.Add(pin);
            map.CustomPins.Add(pin);

}

If i put a break inside the handler, only in android is executed while in IOS is ignored.
Do you have some suggestions about it? Im not sure if it is a custom renderer problem, since the event is not in the renderer, but maybe im missing something?
Thanks a lot for your help!