ListBoxItem is going to the last position when dragged and dropped in to the SCrollViewer.

ListBoxItem disappears when the item is dropped in the RadGridView

Scroll button is changing size when grouping is applied (WPF only).

Add SelectedItemsSource property which can be bound to a collection in the view model. In this case when the RadListBox is in Multiple/Extender mode, the selection can be manipulate from the ViewModel.