There are large number of items for the TreeList (for example 3000) and you have all them initially collapsed.
For example you could modify the IsExpandedBinding demo to have 3000 items.
Then scroll down so the row with Drinks and Count = 2194 is at the top of the control and expand it.
The result is that both that row and the row with Drinks and Count = 2199 expand.

TreeListView root note collapses after scrolling.

TreeListView is trying to expand its item which is empty.

An exception is thrown when you try to update the items source of RadTreeListView in an async method.

The following error is observed.
InvalidOperationException: The calling thread cannot access this object because a different thread owns it

To work this around ensure that only the main UI thread updates the item source.

If you press Ctrl+Up/Down to change the selection and currency in TreeListView, the CurrentCellChanged event is fired. However, the e.NewCell property of the event arguments is null.

To get the new cell, use the CurrentCellInfo property of RadTreeListView.

private void RadTreeListView_CurrentCellChanged(object sender, GridViewCurrentCellChangedEventArgs e)
{
	var treeListView = (RadTreeListView)sender;
	GridViewCellInfo currentCell = treeListView.CurrentCellInfo;
}

Per the thread at "http://www.telerik.com/forums/isexpandablebinding-requires-user-interaction-with-control-to-take-effect" I have modified the IsExpandedRowBinding sample to recreate the problem. I modified the button to expand and collapse the first row. To reproduce the problem:

1. Expand the first row.
2. Scroll down so the first row is not visible but it's children are visible.
3. Press the button. The expected behavior is the first row should collapse but nothing happens.
4. Scroll up so the first row is visible. The first row collapses.

Keyboard navigation stops working when setting SelectionMode to "Extended", SelectionUnit to "Cell"  and pressing twice the down keyboard key . 

The problem should be resolved with version Q1 2016.