Hi Paul Gallen,
Thank you for writing.
Indeed, the Selecting event is not fired if you click on the same node and this is by design. It should fired only when selection has changed. If you want to handle a click on the same node you have to use other suitable events, for example: NodeMouseDown.
Concerning the OnSelectionChanged method, it helps only in internal implementation of RadTreeView events. That is the reason that it is marked as Obsolete and should not be used.
If you have other questions, do not hesitate to contact me again.
the Telerik team
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