Often, when right clicking in a diagram to invoke the context menu, the diagram “shifts” a small amount before the menu appears. The direction of the shift varies. In any case, the highlighted element may end up being different than the one I intended to click on.
Sometimes it doesn’t happen. I think it only happens when the entire diagram does not fit into the view window. Every diagram type I’ve tested has this behavior.
The same happens in the Model Explorer as well. (Shifts up)