fix: fixed #997

Author: NaBian

src/Shared/HandyControl_Shared/Controls/SideMenu/SideMenu.cs

@@ -95,6 +95,12 @@ private void SideMenuItemSelected(object sender, RoutedEventArgs e)
                     {
                         if (AutoSelect)
                         {
+                            if (_selectedItem != null)
+                            {
+                                _selectedItem.IsSelected = false;
+                                _selectedItem = null;
+                            }
+
                             _selectedHeader.SelectDefaultItem();
                         }
                         _isItemSelected = false;