I define two different diagrams such as A diagram and B diagram. When user drag a shape I use my own way to control the behaviour. So I need to create my own InteractionState object and also need to add a shape to show where these shapes will go. Let me call the new added shape as TrackNode.

When I move TrackNode, method "DrawLocal" of TableNode will be called and method "DrawHandles" will not be called. I override these 2 methods and do some work to get this conclusion. But these is one thing is very wired. On A diagram when I move TrackNode, handle rectangle around every selected shape, and on B diagram nothing around these selected shapes.

I already compare every difference that I can compare and try to find why but I get nothing. So I just simply ask a question: is there any thing or default behaviour can cause this difference?