TreeView (QQC2) does not respond properly to mouse clicks

Using the TreeView component (from MarketPLace - not QQC1) when used with a QAbstractItemModel with nested levels.  It renders properly, and I can navigate the tree up/down expand/collapse properly using the keyboard.

 
But - Mouse clicks will not change the current model index, (i.e. unresponsive) UNTIL....I click the expand icon on an item with children. After that it works fine. (Or until after I expand an item using the keyboard).

I have attached a complete example program demonstrating the strange behavior.  As I'm new to bug reporting and QML, apologies if this is a user error (but the example is pretty simple)