Maps Customrenderer not showing route

Hello guys

I am creating an app that uses the Xamarin.Forms.Maps package with a custom renderer in order to show a route starting from my current position to a specific point. It turns out that after asking for permission, if i just hardcode some coordinates, the map is shown correctly with a route tracked on it but as soon as I try to get some more information, for example awaiting a call to an api like google directions, my route is not shown anymore on the map.

What am I doing wrong? Could it be, that the map is shown before all my coordinates are loaded and passed to the map? In that case, how do i force the map to reload?

Here is a sample of my actual code:

            async void GetPermissions()
            {
                try
                {
                    var status = await CrossPermissions.Current.CheckPermissionStatusAsync(Permission.LocationAlways);
                    if (status != PermissionStatus.Granted)
                    {
                        if (await CrossPermissions.Current.ShouldShowRequestPermissionRationaleAsync(Permission.LocationAlways))
                        {
                            Device.BeginInvokeOnMainThread(async () =>
                            {
                                await DisplayAlert("Need location", "I need your location to get a route", "OK");
                            });
                        }

                        var results = await CrossPermissions.Current.RequestPermissionsAsync(Permission.LocationAlways);
                        status = results[Permission.LocationAlways];
                    }

                    var meetingPoint = await App.RestService.GetResponse<MapPosition>("/offers/" + product.Uuid + "/meetingpoint");
                    if (meetingPoint.MyPosition.Latitude != 0 && meetingPoint.MyPosition.Longitude != 0)
                    {
                        var position = new Position(meetingPoint.MyPosition.Latitude, meetingPoint.MyPosition.Longitude);
                        var pin = new Pin
                        {
                            Type = PinType.Place,
                            Position = position,
                            Label = "Meeting for " + product.Title,
                            Address = "Bla bla bla bla bla"
                        };
                        MyMap.Pins.Add(pin);
                    }
                    else
                    {
                        MyMap.MoveToRegion(MapSpan.FromCenterAndRadius(new Position(47.4972279, 8.7271877),
                                                                       Xamarin.Forms.Maps.Distance.FromKilometers(1)));
                    }

                    if (status == PermissionStatus.Granted)
                    {
                        MyMap.IsShowingUser = true;
                        double lat = 0;
                        double lng = 0;

                        try
                        {
                            var location = await Geolocation.GetLastKnownLocationAsync();

                            if (location != null)
                            {
                                lat = location.Latitude;
                                lng = location.Longitude;
                            }
                        }
                        catch (Exception)
                        {
                            await DisplayAlert("Location Error", "I couldn't load your current location. Try again.", "OK");
                            return;
                        }

                        //...... some irrelevant code ......

                        if (meetingPoint.MyPosition.Latitude != 0 && meetingPoint.MyPosition.Longitude != 0)
                        {
                            var geoLocation = await App.RestService.GetExtResponse<GeoLocation>(
                                "LINK_TO_GOOGLE_MAPS_API");

                            if (geoLocation.Status.Equals("OK"))
                            {
                                // get all coordinates
                                // var startLocation = geoLocation.Routes[0].Legs[0].Steps[0].Start_Location;

                                foreach (Step step in geoLocation.Routes[0].Legs[0].Steps)
                                {
                                    var polyline = GooglePoints.Decode(step.Polyline.Points);

                                    foreach (var l in polyline)
                                    {
                                        // HERE I ADD MY COORDINATES TO THE MAP
                                        // RouteCoordinates is a list of Positions, as suggested in the Xamarin Docs
                                        MyMap.RouteCoordinates.Add(new Position(l.Latitude, l.Longitude));
                                    }
                                }

                                var bounds = new List<Position>()
                                {
                                    new Position(geoLocation.Routes[0].Bounds.NorthEast.Lat, geoLocation.Routes[0].Bounds.NorthEast.Lng),
                                    new Position(geoLocation.Routes[0].Bounds.SouthWest.Lat, geoLocation.Routes[0].Bounds.SouthWest.Lng)
                                };

                                MyMap.MoveToRegion(MapSpan.FromCenterAndRadius(Tools.GetCentralGeoCoordinate(bounds),
                                                                           Xamarin.Forms.Maps.Distance.FromMeters(geoLocation.Routes[0].Legs[0].Distance.Value / 2)));
                            }
                            else
                            {
                                //...... some irrelevant code ......
                            }
                        }
                    }
                    else if (status != PermissionStatus.Unknown)
                    {
                        //...... some irrelevant code ......
                    }
                }
                catch (Exception)
                {
                    //...... some irrelevant code ......~~~~
                }
            }

The CustomMapRenderer is just copy pasted from the xamarin docs.