fix(ColorPicker): tooltip of ColorPickerSlider doesn't work properly

src/Uno.UI/Microsoft/UI/Xaml/Controls/ColorPicker/ColorPickerSlider.cs

@@ -17,7 +17,7 @@ public partial class ColorPickerSlider : Slider
 	{
 		private ToolTip m_toolTip;
 
-		public ColorPickerSlider()
+		public ColorPickerSlider() : base()
 		{
 			// We want the ColorPickerSlider to pick up everything for its default style from the Slider's default style,
 			// since its purpose is just to turn off keyboarding.  So we'll give it Slider's control name as its default style key
@@ -42,6 +42,7 @@ protected override void OnApplyTemplate()
 
 			if (m_toolTip is ToolTip toolTip)
 			{
+				_isCustomThumbToolTipEnabled = true;
 				toolTip.Content = GetToolTipString();
 			}
 		}
@@ -172,11 +173,8 @@ private void OnValueChangedEvent(object sender, RangeBaseValueChangedEventArgs a
 			if (m_toolTip is ToolTip toolTip)
 			{
 				toolTip.Content = GetToolTipString();
-
-				// ToolTip doesn't currently provide any way to re-run its placement logic if its placement target moves,
-				// so toggling IsEnabled induces it to do that without incurring any visual glitches.
-				toolTip.IsEnabled = false;
-				toolTip.IsEnabled = true;
+				if (Thumb.IsDragging)
+					UpdateThumbToolTipVisibility(true);
 			}
 
 			DependencyObject currentObject = this;

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

@@ -41,6 +41,7 @@ public Slider()
 		_usingDefaultToolTipForHorizontalThumb = false;
 		_usingDefaultToolTipForVerticalThumb = false;
 		_capturedPointerId = 0;
+		_isCustomThumbToolTipEnabled = false;
 
 		// TODO Uno specific: This is called by DirectUI automatically,
 		// we have to do it manually here.
@@ -1073,6 +1074,7 @@ private void UpdateTrackLayout(
 		actualHeight = Math.Max(actualHeight - padding.Top - padding.Bottom, 0.0);
 
 		isThumbToolTipEnabled = IsThumbToolTipEnabled;
+		isThumbToolTipEnabled |= _isCustomThumbToolTipEnabled;
 #if HAS_UNO
 		isThumbToolTipEnabled &= FeatureConfiguration.ToolTip.UseToolTips;
 #endif

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

@@ -114,4 +114,7 @@ public partial class Slider
 
 	private bool _disengagedWithA;
 
+	// This flag is used for the Thumb ToolTip of ColorPickerSlider
+	protected bool _isCustomThumbToolTipEnabled;
+
 }

src/Uno.UI/UI/Xaml/Controls/ToolTip/ToolTip.cs

@@ -123,7 +123,7 @@ private Size GetTooltipSize()
 		private void OnOpenChanged(bool isOpen)
 		{
 			PerformPlacementInternal();
-			if (_owner is not null)
+			if (_owner is not null && Popup.XamlRoot is null)
 			{
 				XamlRoot = XamlRoot.GetForElement(_owner);
 				Popup.XamlRoot = XamlRoot.GetForElement(_owner);