1. End key does not work correctly when margin is set in the DataTemplate. Actually there is a small missmatch between the real "End" position and the one displayed by the tree.
2. When the IsAsynch property is used inside the binding of the ItemsSource property the End key does not work at all.

The XAML team has recently reviewed this issue and will not be addressing it as at this time the team is focusing on the bugs impacting the highest number of developers. If you have encountered this issue and it is blocking for your work please contact us through the support ticketing system with details on your setup and a reference to this item.