chore: Fix toggle button reliability

src/Uno.UI/UI/Xaml/Controls/AppBar/AppBar.Partial.cs

@@ -7,13 +7,10 @@
 #endif
 
 using System;
-using System.Collections.Generic;
-using System.Text;
 using DirectUI;
 using Uno.Disposables;
 using Uno.UI;
 using Uno.UI.Helpers.WinUI;
-using Windows.ApplicationModel.Resources;
 using Windows.Foundation;
 using Microsoft.UI.Xaml.Controls.Primitives;
 using Microsoft.UI.Xaml.Input;
@@ -23,14 +20,10 @@
 using Uno.UI.Extensions;
 using static Microsoft/* UWP don't rename */.UI.Xaml.Controls._Tracing;
 using Uno.UI.Xaml.Input;
-using System.Linq;
-using Microsoft.UI.Xaml.Controls;
-using Microsoft.UI.Xaml;
 using Popup = Microsoft.UI.Xaml.Controls.Primitives.Popup;
 using Windows.System;
 using Microsoft.UI.Xaml.Automation.Peers;
 using Microsoft.UI.Xaml.Automation;
-using Uno.UI.Controls;
 using Uno.UI.Xaml.Core;
 using WinUICoreServices = Uno.UI.Xaml.Core.CoreServices;
 
@@ -73,7 +66,7 @@ public partial class AppBar : ContentControl
 		WeakReference<Page>? m_wpOwner;
 
 		SerialDisposable m_contentRootSizeChangedEventHandler = new SerialDisposable();
-		SerialDisposable m_windowSizeChangedEventHandler = new SerialDisposable();
+		SerialDisposable m_xamlRootChangedEventHandler = new SerialDisposable();
 		SerialDisposable m_expandButtonClickEventHandler = new SerialDisposable();
 		SerialDisposable m_displayModeStateChangedEventHandler = new SerialDisposable();
 
@@ -148,10 +141,10 @@ private protected override void OnLoaded()
 			}
 
 			// TODO: Uno specific - use XamlRoot instead of Window
-			if (XamlRoot is not null)
+			if (m_xamlRootChangedEventHandler.Disposable is null && XamlRoot is not null)
 			{
 				XamlRoot.Changed += OnXamlRootChanged;
-				m_windowSizeChangedEventHandler.Disposable = Disposable.Create(() => XamlRoot.Changed -= OnXamlRootChanged);
+				m_xamlRootChangedEventHandler.Disposable = Disposable.Create(() => XamlRoot.Changed -= OnXamlRootChanged);
 			}
 
 			//UNO TODO
@@ -253,19 +246,7 @@ protected override void OnVisibilityChanged(Visibility oldValue, Visibility newV
 		}
 		private void UnregisterEvents()
 		{
-			m_contentRootSizeChangedEventHandler.Disposable = null;
-			m_windowSizeChangedEventHandler.Disposable = null;
-			m_expandButtonClickEventHandler.Disposable = null;
-			m_displayModeStateChangedEventHandler.Disposable = null;
-			m_overlayElementPointerPressedEventHandler.Disposable = null;
-
-			m_tpLayoutRoot = null;
-			m_tpContentRoot = null;
-			m_tpExpandButton = null;
-			m_tpDisplayModesStateGroupRef = null;
-
-			m_overlayClosingStoryboard = null;
-			m_overlayOpeningStoryboard = null;
+			m_xamlRootChangedEventHandler.Disposable = null;
 		}
 
 		private protected override void OnUnloaded()
@@ -285,7 +266,28 @@ private protected override void OnUnloaded()
 
 		protected override void OnApplyTemplate()
 		{
-			UnregisterEvents();
+			if (m_tpContentRoot is not null)
+			{
+				m_contentRootSizeChangedEventHandler.Disposable = null;
+			}
+
+			if (m_tpExpandButton is not null)
+			{
+				m_expandButtonClickEventHandler.Disposable = null;
+			}
+
+			if (m_tpDisplayModesStateGroupRef is not null)
+			{
+				m_displayModeStateChangedEventHandler.Disposable = null;
+			}
+
+			m_tpLayoutRoot = null;
+			m_tpContentRoot = null;
+			m_tpExpandButton = null;
+			m_tpDisplayModesStateGroupRef = null;
+
+			m_overlayClosingStoryboard = null;
+			m_overlayOpeningStoryboard = null;
 
 			// Clear our previous template parts.
 			m_tpLayoutRoot = null;

src/Uno.UI/UI/Xaml/Controls/CommandBar/CommandBarOverflowPresenter.mux.cs

@@ -22,8 +22,8 @@ public CommandBarOverflowPresenter()
 		m_useFullWidth = false;
 		m_shouldOpenUp = false;
 
-#if HAS_UNO && XAMARIN // Uno specific: Set StackPanel as default ItemsPanel for CommandBarOverflowPresenter
-		ItemsPanel = new ItemsPanelTemplate(() => new StackPanel());
+#if HAS_UNO // Uno specific: Set StackPanel as default ItemsPanel for CommandBarOverflowPresenter
+		ItemsPanel = new ItemsPanelTemplate(() => new StackPanel() { HorizontalAlignment = HorizontalAlignment.Stretch });
 #endif
 	}
 

src/Uno.UI/UI/Xaml/Controls/CommandBarFlyout/CommandBarFlyout.h.mux.cs

@@ -62,7 +62,7 @@ public bool AlwaysExpanded
 	private readonly Dictionary<int, IDisposable> m_secondaryToggleButtonUncheckedRevokerByIndexMap = new();
 	private readonly Dictionary<int, IDisposable[]> m_propertyChangedRevokersByIndexMap = new();
 
-	private FlyoutPresenter? m_presenter = null;
+	private FlyoutPresenter? m_presenter;
 
-	private bool m_isClosingAfterCloseAnimation = false;
+	private bool m_isClosingAfterCloseAnimation;
 }

src/Uno.UI/UI/Xaml/Controls/CommandBarFlyout/CommandBarFlyout.mux.cs

@@ -416,6 +416,7 @@ void closeFlyoutFunc(object sender, object args)
 				button.Click += closeFlyoutFunc;
 				var clickRevoker = new SerialDisposable();
 				clickRevoker.Disposable = Disposable.Create(() => button.Click -= closeFlyoutFunc);
+				m_secondaryButtonClickRevokerByIndexMap[i] = clickRevoker;
 			}
 			else if (toggleButton is not null)
 			{

src/Uno.UI/UI/Xaml/Controls/CommandBarFlyout/TextCommandBarFlyout.h.mux.cs

@@ -44,5 +44,5 @@ partial class TextCommandBarFlyout
 	private List<IDisposable> m_proofingMenuToggleItemClickRevokers = new();
 	private DispatcherHelper m_dispatcherHelper;
 
-	private bool m_isSettingToggleButtonState = false;
+	private bool m_isSettingToggleButtonState;
 }