Update dynamic resources on set parent.

src/Avalonia.Controls/Control.cs

@@ -521,6 +521,7 @@ namespace Avalonia.Controls
                 }
 
                 _parent = (IControl)parent;
+                ((ILogical)this).NotifyResourcesChanged(new ResourcesChangedEventArgs());
 
                 if (_parent is IStyleRoot || _parent?.IsAttachedToLogicalTree == true || this is IStyleRoot)
                 {

tests/Avalonia.Markup.Xaml.UnitTests/MarkupExtensions/DynamicResourceExtensionTests.cs

@@ -393,6 +393,38 @@ namespace Avalonia.Markup.Xaml.UnitTests.MarkupExtensions
             }
         }
 
+        [Fact]
+        public void Control_Property_Is_Updated_When_Parent_Is_Changed()
+        {
+            var xaml = @"
+<UserControl xmlns='https://github.com/avaloniaui'
+             xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'>
+    <UserControl.Resources>
+        <SolidColorBrush x:Key='brush'>#ff506070</SolidColorBrush>
+    </UserControl.Resources>
+
+    <Border Name='border' Background='{DynamicResource brush}'/>
+</UserControl>";
+
+            var loader = new AvaloniaXamlLoader();
+            var userControl = (UserControl)loader.Load(xaml);
+            var border = userControl.FindControl<Border>("border");
+
+            DelayedBinding.ApplyBindings(border);
+
+            var brush = (SolidColorBrush)border.Background;
+            Assert.Equal(0xff506070, brush.Color.ToUint32());
+
+            userControl.Content = null;
+
+            Assert.Null(border.Background);
+
+            userControl.Content = border;
+
+            brush = (SolidColorBrush)border.Background;
+            Assert.Equal(0xff506070, brush.Color.ToUint32());
+        }
+
         private IDisposable StyledWindow(params (string, string)[] assets)
         {
             var services = TestServices.StyledWindow.With(