If you have a RadComboBox inside a ControlPanelItem, when you open the RadComboBox's dropdown and select an item, the ControlPanelItem is not closed. As a workaround, you can manually capture the mouse. Please check the attached project.

Currently, RadGridView's data engine relies on TypeDescriptor.GetProperties, when resolving the set of properties accessible through a certain type. Apparently, this API hides the properteis from the interface, as they are not accessible throught the concrete type.

The unconfirmed inputs of filter row editors are being destroyed together with the editor itself in column-visualized GridViews. There's an easy solution for it (store what was in there and restore upon recreation) and we're waiting for an official fix for this "expected behaviour" since three+ years.

Similar to the one in RadPivotGrid:
https://docs.telerik.com/devtools/wpf/controls/radpivotgrid/features/localdatasourceprovider/serialization

And here is an online demo:
https://demos.telerik.com/silverlight/#PivotGrid/Serialization

When setting the VirtualItemCount on refreshing the data source, the scrollbar jumps to the top. If the VirtualItemCount is initially set, the behavior is not reproduced. The workaround is to use the scrolling mechanism of the control and scroll back to the desired item.

Currently, you can use only the predefined one - IsEqual, IsNotEqual, etc. Add an option to create operators that execute custom filtering action. Also, add support for modifying the default operators.

Currently, the following workaround can be applied:

private void RadGridView_Loaded(object sender, RoutedEventArgs e)
{
	var gridView = sender as RadGridView;
	foreach (var column in gridView.Columns)
	{
		if (!column.IsResizable)
		{
			Dispatcher.BeginInvoke((Action) (() =>
			{
				var radGridView = column.Parent;
				foreach (var header in radGridView.ChildrenOfType<GridViewHeaderCell>())
				{
					if (header.Column.DisplayIndex == column.DisplayIndex)
					{
						var leftGripper = header.ChildrenOfType<Thumb>().Where(x => x.Name == "PART_LeftHeaderGripper").First();
						{
							leftGripper.Visibility = Visibility.Collapsed;
						}
					}
					else if (header.Column.DisplayIndex == (column.DisplayIndex - 1))
					{
						var rightGripper = header.ChildrenOfType<Thumb>().Where(x => x.Name == "PART_RightHeaderGripper").First();
						{
							rightGripper.Visibility = Visibility.Collapsed;
						}
					}
				}
			}), DispatcherPriority.Render);
		}
	}
}

Same as the one available in Excel. Please check the attached screenshot.

This is reproducible in a hierarchical scenario. The nested gridview loses its selection when its parent row is scrolled out of the viewport.