Try to fix last known position reset

src/Avalonia.Base/Input/PointerOverPreProcessor.cs

@@ -6,7 +6,8 @@ namespace Avalonia.Input
     internal class PointerOverPreProcessor : IObserver<RawInputEventArgs>
     {
         private IPointerDevice? _lastActivePointerDevice;
-        private (IPointer pointer, PixelPoint position)? _lastPointer;
+        private (IPointer pointer, PixelPoint position)? _currentPointer;
+        private PixelPoint? _lastKnownPosition;
 
         private readonly IInputRoot _inputRoot;
 
@@ -15,7 +16,7 @@ namespace Avalonia.Input
             _inputRoot = inputRoot ?? throw new ArgumentNullException(nameof(inputRoot));
         }
 
-        public PixelPoint? LastPosition => _lastPointer?.position;
+        public PixelPoint? LastPosition => _lastKnownPosition;
         
         public void OnCompleted()
         {
@@ -41,9 +42,9 @@ namespace Avalonia.Input
                 }
 
                 if (args.Type is RawPointerEventType.LeaveWindow or RawPointerEventType.NonClientLeftButtonDown
-                    && _lastPointer is (var lastPointer, var lastPosition))
+                    && _currentPointer is (var lastPointer, var lastPosition))
                 {
-                    _lastPointer = null;
+                    _currentPointer = null;
                     ClearPointerOver(lastPointer, args.Root, 0, PointToClient(args.Root, lastPosition),
                         new PointerPointProperties(args.InputModifiers, args.Type.ToUpdateKind()),
                         args.InputModifiers.ToKeyModifiers());
@@ -62,7 +63,7 @@ namespace Avalonia.Input
 
         public void SceneInvalidated(Rect dirtyRect)
         {
-            if (_lastPointer is (var pointer, var position))
+            if (_currentPointer is (var pointer, var position))
             {
                 var clientPoint = PointToClient(_inputRoot, position);
 
@@ -80,12 +81,12 @@ namespace Avalonia.Input
 
         private void ClearPointerOver()
         {
-            if (_lastPointer is (var pointer, var position))
+            if (_currentPointer is (var pointer, var position))
             {
                 var clientPoint = PointToClient(_inputRoot, position);
                 ClearPointerOver(pointer, _inputRoot, 0, clientPoint, PointerPointProperties.None, KeyModifiers.None);
             }
-            _lastPointer = null;
+            _currentPointer = null;
             _lastActivePointerDevice = null;
         }
 
@@ -122,7 +123,7 @@ namespace Avalonia.Input
 
             root.PointerOverElement = null;
             _lastActivePointerDevice = null;
-            _lastPointer = null;
+            _currentPointer = null;
         }
 
         private void ClearChildrenPointerOver(PointerEventArgs e, IInputElement element, bool clearRoot)
@@ -164,7 +165,9 @@ namespace Avalonia.Input
                 }
             }
 
-            _lastPointer = (pointer, ((Visual)root).PointToScreen(position));
+            var screenPosition = ((Visual)root).PointToScreen(position);
+            _lastKnownPosition = screenPosition;
+            _currentPointer = (pointer, screenPosition);
         }
 
         private void SetPointerOverToElement(IPointer pointer, IInputRoot root, IInputElement element,