diff --git a/src/Avalonia.Base/Data/Core/IndexerNodeBase.cs b/src/Avalonia.Base/Data/Core/IndexerNodeBase.cs
index 9ec256225b..57e4fa4a8e 100644
--- a/src/Avalonia.Base/Data/Core/IndexerNodeBase.cs
+++ b/src/Avalonia.Base/Data/Core/IndexerNodeBase.cs
@@ -22,7 +22,7 @@ namespace Avalonia.Data.Core
 
             if (target is INotifyPropertyChanged inpc)
             {
-                WeakEvents.PropertyChanged.Subscribe(inpc, this);
+                WeakEvents.ThreadSafePropertyChanged.Subscribe(inpc, this);
             }
             
             ValueChanged(GetValue(target));
@@ -39,7 +39,7 @@ namespace Avalonia.Data.Core
 
                 if (target is INotifyPropertyChanged inpc)
                 {
-                    WeakEvents.PropertyChanged.Unsubscribe(inpc, this);
+                    WeakEvents.ThreadSafePropertyChanged.Unsubscribe(inpc, this);
                 }
             }
         }
diff --git a/src/Avalonia.Base/Data/Core/Plugins/InpcPropertyAccessorPlugin.cs b/src/Avalonia.Base/Data/Core/Plugins/InpcPropertyAccessorPlugin.cs
index 7c2caf02b4..e8e3e6d509 100644
--- a/src/Avalonia.Base/Data/Core/Plugins/InpcPropertyAccessorPlugin.cs
+++ b/src/Avalonia.Base/Data/Core/Plugins/InpcPropertyAccessorPlugin.cs
@@ -160,7 +160,7 @@ namespace Avalonia.Data.Core.Plugins
                 var inpc = GetReferenceTarget() as INotifyPropertyChanged;
 
                 if (inpc != null) 
-                    WeakEvents.PropertyChanged.Unsubscribe(inpc, this);
+                    WeakEvents.ThreadSafePropertyChanged.Unsubscribe(inpc, this);
             }
 
             private object? GetReferenceTarget()
@@ -185,7 +185,7 @@ namespace Avalonia.Data.Core.Plugins
                 var inpc = GetReferenceTarget() as INotifyPropertyChanged;
 
                 if (inpc != null) 
-                    WeakEvents.PropertyChanged.Subscribe(inpc, this);
+                    WeakEvents.ThreadSafePropertyChanged.Subscribe(inpc, this);
             }
         }
     }
diff --git a/src/Avalonia.Base/Utilities/WeakEvents.cs b/src/Avalonia.Base/Utilities/WeakEvents.cs
index 6da899bab2..2f62564e0e 100644
--- a/src/Avalonia.Base/Utilities/WeakEvents.cs
+++ b/src/Avalonia.Base/Utilities/WeakEvents.cs
@@ -2,6 +2,7 @@ using System;
 using System.Collections.Specialized;
 using System.ComponentModel;
 using System.Windows.Input;
+using Avalonia.Threading;
 
 namespace Avalonia.Utilities;
 
@@ -20,15 +21,30 @@ public class WeakEvents
             });
     
     /// <summary>
-    /// Represents PropertyChanged event from <see cref="INotifyPropertyChanged"/>
+    /// Represents PropertyChanged event from <see cref="INotifyPropertyChanged"/> with auto-dispatching to the UI thread
     /// </summary>
     public static readonly WeakEvent<INotifyPropertyChanged, PropertyChangedEventArgs>
-        PropertyChanged = WeakEvent.Register<INotifyPropertyChanged, PropertyChangedEventArgs>(
+        ThreadSafePropertyChanged = WeakEvent.Register<INotifyPropertyChanged, PropertyChangedEventArgs>(
             (s, h) =>
             {
-                PropertyChangedEventHandler handler = (_, e) => h(s, e);
+                bool unsubscribed = false;
+                PropertyChangedEventHandler handler = (_, e) =>
+                {
+                    if (Dispatcher.UIThread.CheckAccess())
+                        h(s, e);
+                    else
+                        Dispatcher.UIThread.Post(() =>
+                        {
+                            if (!unsubscribed)
+                                h(s, e);
+                        });
+                };
                 s.PropertyChanged += handler;
-                return () => s.PropertyChanged -= handler;
+                return () =>
+                {
+                    unsubscribed = true;
+                    s.PropertyChanged -= handler;
+                };
             });
 
 
diff --git a/src/Avalonia.Controls/RelativePanel.AttachedProperties.cs b/src/Avalonia.Controls/RelativePanel.AttachedProperties.cs
index 18cf96ddca..d2b91def7d 100644
--- a/src/Avalonia.Controls/RelativePanel.AttachedProperties.cs
+++ b/src/Avalonia.Controls/RelativePanel.AttachedProperties.cs
@@ -1,37 +1,30 @@
 using Avalonia.Layout;
+using Avalonia.Threading;
 
 namespace Avalonia.Controls
 {
     public partial class RelativePanel
     {
-        private static void OnAlignPropertiesChanged(AvaloniaObject d, AvaloniaPropertyChangedEventArgs e)
-        {
-            if (d is Layoutable layoutable && layoutable.Parent is Layoutable layoutableParent)
-            {
-                layoutableParent.InvalidateArrange();
-            }
-        }
 
         static RelativePanel()
         {
             ClipToBoundsProperty.OverrideDefaultValue<RelativePanel>(true);
 
-            AboveProperty.Changed.AddClassHandler<Layoutable>(OnAlignPropertiesChanged);
-            AlignBottomWithPanelProperty.Changed.AddClassHandler<Layoutable>(OnAlignPropertiesChanged);
-            AlignBottomWithProperty.Changed.AddClassHandler<Layoutable>(OnAlignPropertiesChanged);
-            AlignHorizontalCenterWithPanelProperty.Changed.AddClassHandler<Layoutable>(OnAlignPropertiesChanged);
-            AlignHorizontalCenterWithProperty.Changed.AddClassHandler<Layoutable>(OnAlignPropertiesChanged);
-            AlignLeftWithPanelProperty.Changed.AddClassHandler<Layoutable>(OnAlignPropertiesChanged);
-            AlignLeftWithProperty.Changed.AddClassHandler<Layoutable>(OnAlignPropertiesChanged);
-            AlignRightWithPanelProperty.Changed.AddClassHandler<Layoutable>(OnAlignPropertiesChanged);
-            AlignRightWithProperty.Changed.AddClassHandler<Layoutable>(OnAlignPropertiesChanged);
-            AlignTopWithPanelProperty.Changed.AddClassHandler<Layoutable>(OnAlignPropertiesChanged);
-            AlignTopWithProperty.Changed.AddClassHandler<Layoutable>(OnAlignPropertiesChanged);
-            AlignVerticalCenterWithPanelProperty.Changed.AddClassHandler<Layoutable>(OnAlignPropertiesChanged);
-            AlignVerticalCenterWithProperty.Changed.AddClassHandler<Layoutable>(OnAlignPropertiesChanged);
-            BelowProperty.Changed.AddClassHandler<Layoutable>(OnAlignPropertiesChanged);
-            LeftOfProperty.Changed.AddClassHandler<Layoutable>(OnAlignPropertiesChanged);
-            RightOfProperty.Changed.AddClassHandler<Layoutable>(OnAlignPropertiesChanged);
+            AffectsParentArrange<RelativePanel>(
+                AlignLeftWithPanelProperty, AlignLeftWithProperty, LeftOfProperty,
+                AlignRightWithPanelProperty, AlignRightWithProperty, RightOfProperty,
+                AlignTopWithPanelProperty, AlignTopWithProperty, AboveProperty,
+                AlignBottomWithPanelProperty, AlignBottomWithProperty, BelowProperty,
+                AlignHorizontalCenterWithPanelProperty, AlignHorizontalCenterWithProperty,
+                AlignVerticalCenterWithPanelProperty, AlignVerticalCenterWithProperty);
+            
+            AffectsParentMeasure<RelativePanel>(
+                AlignLeftWithPanelProperty, AlignLeftWithProperty, LeftOfProperty,
+                AlignRightWithPanelProperty, AlignRightWithProperty, RightOfProperty,
+                AlignTopWithPanelProperty, AlignTopWithProperty, AboveProperty,
+                AlignBottomWithPanelProperty, AlignBottomWithProperty, BelowProperty,
+                AlignHorizontalCenterWithPanelProperty, AlignHorizontalCenterWithProperty,
+                AlignVerticalCenterWithPanelProperty, AlignVerticalCenterWithProperty);
         }
 
         /// <summary>
diff --git a/src/Avalonia.Diagnostics/Diagnostics/Controls/FilterTextBox.axaml b/src/Avalonia.Diagnostics/Diagnostics/Controls/FilterTextBox.axaml
index 3bfe511fbc..1b5f431f36 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/Controls/FilterTextBox.axaml
+++ b/src/Avalonia.Diagnostics/Diagnostics/Controls/FilterTextBox.axaml
@@ -16,6 +16,8 @@
         <StackPanel Orientation="Horizontal" Spacing="1">
           <Button Margin="0,0,2,0"
                   Classes="textBoxClearButton"
+                  Theme="{StaticResource SimpleTextBoxClearButtonTheme}"
+                  Focusable="False"
                   ToolTip.Tip="Clear"
                   Cursor="Hand"
                   Command="{Binding $parent[TextBox].Clear}"
diff --git a/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlLayoutViewModel.cs b/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlLayoutViewModel.cs
index 6b56806250..efa93ce52e 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlLayoutViewModel.cs
+++ b/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlLayoutViewModel.cs
@@ -103,13 +103,13 @@ namespace Avalonia.Diagnostics.ViewModels
         public HorizontalAlignment HorizontalAlignment
         {
             get => _horizontalAlignment;
-            private set => RaiseAndSetIfChanged(ref _horizontalAlignment, value);
+            set => RaiseAndSetIfChanged(ref _horizontalAlignment, value);
         }
 
         public VerticalAlignment VerticalAlignment
         {
             get => _verticalAlignment;
-            private set => RaiseAndSetIfChanged(ref _verticalAlignment, value);
+            set => RaiseAndSetIfChanged(ref _verticalAlignment, value);
         }
 
         public bool HasPadding { get; }
diff --git a/src/Markup/Avalonia.Markup.Xaml/MarkupExtensions/CompiledBindings/PropertyInfoAccessorFactory.cs b/src/Markup/Avalonia.Markup.Xaml/MarkupExtensions/CompiledBindings/PropertyInfoAccessorFactory.cs
index abb166a92b..9e58f81b55 100644
--- a/src/Markup/Avalonia.Markup.Xaml/MarkupExtensions/CompiledBindings/PropertyInfoAccessorFactory.cs
+++ b/src/Markup/Avalonia.Markup.Xaml/MarkupExtensions/CompiledBindings/PropertyInfoAccessorFactory.cs
@@ -121,7 +121,7 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions.CompiledBindings
         {
             if (_reference.TryGetTarget(out var o) && o is INotifyPropertyChanged inpc)
             {
-                WeakEvents.PropertyChanged.Unsubscribe(inpc, this);
+                WeakEvents.ThreadSafePropertyChanged.Unsubscribe(inpc, this);
             }
         }
 
@@ -138,7 +138,7 @@ namespace Avalonia.Markup.Xaml.MarkupExtensions.CompiledBindings
         private void SubscribeToChanges()
         {
             if (_reference.TryGetTarget(out var o) && o is INotifyPropertyChanged inpc)
-                WeakEvents.PropertyChanged.Subscribe(inpc, this);
+                WeakEvents.ThreadSafePropertyChanged.Subscribe(inpc, this);
         }
     }