Fix Changing Location on a Pin does nothing

src/Core/maps/src/Handlers/Map/MapHandler.Android.cs

@@ -422,16 +422,20 @@ void AddPins(IList pins)
 				Marker? marker;
 
 				var pinHandler = pin.ToHandler(MauiContext);
-				if (pinHandler is IMapPinHandler iMapPinHandler)
+				if (pinHandler is MapPinHandler mapPinHandler)
 				{
-					marker = Map.AddMarker(iMapPinHandler.PlatformView);
+					marker = Map.AddMarker(mapPinHandler.PlatformView);
 					if (marker == null)
 					{
 						throw new System.Exception("Map.AddMarker returned null");
 					}
+
+					// Store the marker reference in the MapPinHandler for future property updates
+					mapPinHandler.Marker = marker;
+
 					// associate pin with marker for later lookup in event handlers
 					pin.MarkerId = marker.Id;
-					_markers.Add(marker!);
+					_markers.Add(marker);
 				}
 
 			}

src/Core/maps/src/Handlers/MapPin/MapPinHandler.Android.cs

@@ -1,27 +1,61 @@
-using Android.Gms.Maps;
+using System;
+using Android.Gms.Maps;
 using Android.Gms.Maps.Model;
 using Microsoft.Maui.Handlers;
 
 namespace Microsoft.Maui.Maps.Handlers
 {
 	public partial class MapPinHandler : ElementHandler<IMapPin, MarkerOptions>
 	{
+		// Keep track of the actual marker associated with this handler using a weak reference
+		// to avoid potential memory leaks (the Marker is owned by the Google Maps view)
+		WeakReference<Marker>? _markerWeakReference;
+
+		internal Marker? Marker
+		{
+			get => _markerWeakReference?.TryGetTarget(out var marker) == true ? marker : null;
+			set => _markerWeakReference = value is not null ? new WeakReference<Marker>(value) : null;
+		}
+
 		protected override MarkerOptions CreatePlatformElement() => new MarkerOptions();
 
 		public static void MapLocation(IMapPinHandler handler, IMapPin mapPin)
 		{
-			if (mapPin.Location != null)
-				handler.PlatformView.SetPosition(new LatLng(mapPin.Location.Latitude, mapPin.Location.Longitude));
+			if (mapPin.Location is null)
+			{
+				return;
+			}
+
+			// Always update the MarkerOptions
+			var position = new LatLng(mapPin.Location.Latitude, mapPin.Location.Longitude);
+			handler.PlatformView.SetPosition(position);
+
+			// Update the actual marker if available
+			UpdateMarker(handler, marker => marker.Position = position);
 		}
 
 		public static void MapLabel(IMapPinHandler handler, IMapPin mapPin)
 		{
 			handler.PlatformView.SetTitle(mapPin.Label);
+
+			// Update the actual marker if available
+			UpdateMarker(handler, marker => marker.Title = mapPin.Label);
 		}
 
 		public static void MapAddress(IMapPinHandler handler, IMapPin mapPin)
 		{
 			handler.PlatformView.SetSnippet(mapPin.Address);
+
+			// Update the actual marker if available
+			UpdateMarker(handler, marker => marker.Snippet = mapPin.Address);
+		}
+
+		static void UpdateMarker(IMapPinHandler handler, Action<Marker> updateAction)
+		{
+			if (handler is MapPinHandler mapPinHandler && mapPinHandler.Marker is Marker marker)
+			{
+				updateAction(marker);
+			}
 		}
 	}
 }