A project with problems in RadTreeListView in the attachment.

Description of the project:

The element RadTreeListView have the name ObjectsTree.  As the ItemsSource of ObjectsTree set the child elements of ObjectsTreeViewModel. ObjectsTreeViewModel contains child elements of type ParentNode. The elements of ParentNode have childrens with type ChildNode. (In the project are used 3 ParentNode elements with 3 childNodes at everyone).

ChildNode elements that have the property ShowNode  equals false should not be displayed. To do this, used the FilterDescriptor. The property IsConnected of ChildNode elements sets the ShowNode property (ShowNode = IsConnected).

The button "Node to offline" is used to reset a property IsConnected to the selected ParentNode element and to all of his children.
The button "All Nodes to online" is used to set a property IsConnected to the all ParentNode elements and to all of their children.
The button "Check Memory Leak" is used update ObjectTree 10000 times.
If you check radiobutton "With Rebind" update using Rebind() command
If you check radiobutton "With clearing filter" update using command sequence : FilterDescriptors.Clear -> FilterDescriptors.Add.

Description of the problem:
1)	When updating the tree using the sequence of commands FilterDescriptors.Clear (); FilterDescriptors.Add (...):
The visual element displays the elements of tree correctly, but there is a memory leak.

2)	When updating with Rebind ():
Memory leaks are not present, but we may see following bug:
Select ParentNode.
Press the "Node to offline" button      -> The child elements are hidden, but a triangle for expanding the list elements is visible.
When you click on this triangle            -> it disappears
Press the button "All Nodes to online" ->the children and the triangle do not appear.