diff --git a/Sources/SmartTaskbar.Win10/Worker/Engine.cs b/Sources/SmartTaskbar.Win10/Worker/Engine.cs
index 5f9f558..2a451e6 100644
--- a/Sources/SmartTaskbar.Win10/Worker/Engine.cs
+++ b/Sources/SmartTaskbar.Win10/Worker/Engine.cs
@@ -13,6 +13,7 @@ internal sealed class Engine
         private static int _timerCount;
         private static TaskbarInfo _taskbar;
 
+        private static readonly HashSet<IntPtr> NonMouseOverShowHandleSet = new HashSet<IntPtr>();
         private static readonly HashSet<IntPtr> DesktopHandleSet = new HashSet<IntPtr>();
         private static readonly Stack<IntPtr> LastHideForegroundHandle = new Stack<IntPtr>();
         private static ForegroundWindowInfo _currentForegroundWindow;
@@ -53,7 +54,7 @@ private static void Timer_Tick(object sender, EventArgs e)
                 Hooker.SetHook(_taskbar.Handle);
             }
 
-            switch (_taskbar.CheckIfMouseOver())
+            switch (_taskbar.CheckIfMouseOver(NonMouseOverShowHandleSet))
             {
                 case TaskbarBehavior.DoNothing:
                     break;
@@ -78,6 +79,7 @@ private static void Timer_Tick(object sender, EventArgs e)
             _timerCount = 0;
 
             DesktopHandleSet.Clear();
+            NonMouseOverShowHandleSet.Clear();
             Hooker.ResetHook();
         }
 
diff --git a/Sources/SmartTaskbar.Win10/Worker/TaskbarHelper.cs b/Sources/SmartTaskbar.Win10/Worker/TaskbarHelper.cs
index 2bb1223..b65e15b 100644
--- a/Sources/SmartTaskbar.Win10/Worker/TaskbarHelper.cs
+++ b/Sources/SmartTaskbar.Win10/Worker/TaskbarHelper.cs
@@ -180,9 +180,9 @@ public static void ShowTaskar(this in TaskbarInfo taskbar)
         ///     Mouse over the taskbar or a specific window,
         ///     it will only cause the taskbar to show or do nothing.
         /// </summary>
-        /// <param name="taskbar"></param>
         /// <returns></returns>
-        public static TaskbarBehavior CheckIfMouseOver(this in TaskbarInfo taskbar)
+        public static TaskbarBehavior CheckIfMouseOver(this in TaskbarInfo taskbar,
+                                                       HashSet<IntPtr>     nonMouseOverShowHandleSet)
         {
             // Get mouse coordinates
             if (!GetCursorPos(out var point))
@@ -214,11 +214,19 @@ public static TaskbarBehavior CheckIfMouseOver(this in TaskbarInfo taskbar)
                 && mouseOverRect.right <= taskbar.Rect.right + TrayTolerance)
                 return TaskbarBehavior.DoNothing;
 
-            // If it is a thumbnail of the floating taskbar icon,
-            // the taskbar needs to be displayed.
-            return mouseOverHandle.GetClassName() is TrayTaskListThumbnailWnd
-                ? TaskbarBehavior.Show
-                : TaskbarBehavior.Pending;
+            if (nonMouseOverShowHandleSet.Contains(mouseOverHandle))
+                return TaskbarBehavior.Pending;
+
+            switch (mouseOverHandle.GetClassName())
+            {
+                // If it is a thumbnail of the floating taskbar icon,
+                // the taskbar needs to be displayed.
+                case TrayTaskListThumbnailWnd:
+                    return TaskbarBehavior.Show;
+                default:
+                    nonMouseOverShowHandleSet.Add(mouseOverHandle);
+                    return TaskbarBehavior.Pending;
+            }
         }
 
         public static bool CheckIfWindowShouldHideTaskbar(this in TaskbarInfo taskbar, IntPtr foregroundHandle)
diff --git a/Sources/SmartTaskbar/Worker/Engine.cs b/Sources/SmartTaskbar/Worker/Engine.cs
index f5a6f8e..e0be923 100644
--- a/Sources/SmartTaskbar/Worker/Engine.cs
+++ b/Sources/SmartTaskbar/Worker/Engine.cs
@@ -11,6 +11,7 @@ internal sealed class Engine
         private static int _timerCount;
         private static TaskbarInfo _taskbar;
 
+        private static readonly HashSet<IntPtr> NonMouseOverShowHandleSet = new();
         private static readonly HashSet<IntPtr> DesktopHandleSet = new();
         private static readonly Stack<IntPtr> LastHideForegroundHandle = new();
         private static ForegroundWindowInfo _currentForegroundWindow;
@@ -46,7 +47,7 @@ private static void Timer_Tick(object sender, EventArgs e)
                     return;
             }
 
-            switch (_taskbar.CheckIfMouseOver())
+            switch (_taskbar.CheckIfMouseOver(NonMouseOverShowHandleSet))
             {
                 case TaskbarBehavior.DoNothing:
                     break;
@@ -71,6 +72,7 @@ private static void Timer_Tick(object sender, EventArgs e)
             _timerCount = 0;
 
             DesktopHandleSet.Clear();
+            NonMouseOverShowHandleSet.Clear();
         }
 
         private static void CheckCurrentWindow()
diff --git a/Sources/SmartTaskbar/Worker/TaskbarHelper.cs b/Sources/SmartTaskbar/Worker/TaskbarHelper.cs
index d135495..2c78142 100644
--- a/Sources/SmartTaskbar/Worker/TaskbarHelper.cs
+++ b/Sources/SmartTaskbar/Worker/TaskbarHelper.cs
@@ -176,9 +176,9 @@ public static void ShowTaskar(this in TaskbarInfo taskbar)
         ///     Mouse over the taskbar or a specific window,
         ///     it will only cause the taskbar to show or do nothing.
         /// </summary>
-        /// <param name="taskbar"></param>
         /// <returns></returns>
-        public static TaskbarBehavior CheckIfMouseOver(this in TaskbarInfo taskbar)
+        public static TaskbarBehavior CheckIfMouseOver(this in TaskbarInfo taskbar,
+                                                       HashSet<IntPtr>     nonMouseOverShowHandleSet)
         {
             // Get mouse coordinates
             if (!GetCursorPos(out var point))
@@ -210,11 +210,19 @@ public static TaskbarBehavior CheckIfMouseOver(this in TaskbarInfo taskbar)
                 && mouseOverRect.right <= taskbar.Rect.right + TrayTolerance)
                 return TaskbarBehavior.DoNothing;
 
-            // If it is a thumbnail of the floating taskbar icon,
-            // the taskbar needs to be displayed.
-            return mouseOverHandle.GetClassName() is TrayTaskListThumbnailWnd
-                ? TaskbarBehavior.Show
-                : TaskbarBehavior.Pending;
+            if (nonMouseOverShowHandleSet.Contains(mouseOverHandle))
+                return TaskbarBehavior.Pending;
+
+            switch (mouseOverHandle.GetClassName())
+            {
+                // If it is a thumbnail of the floating taskbar icon,
+                // the taskbar needs to be displayed.
+                case TrayTaskListThumbnailWnd:
+                    return TaskbarBehavior.Show;
+                default:
+                    nonMouseOverShowHandleSet.Add(mouseOverHandle);
+                    return TaskbarBehavior.Pending;
+            }
         }
 
         public static bool CheckIfWindowShouldHideTaskbar(this in TaskbarInfo taskbar, IntPtr foregroundHandle)