It’s a part of Adobe’s help
When nested nodes are involved, mouse events target the deepest possible nested node that is visible in the display list. This node is called the target node. To have a target node’s ancestor receive notification of a mouse event, use EventDispatcher.addEventListener() on the ancestor node with the type parameter set to the specific mouse event you want to detect.
I there a way to catch an event on sibling, not ancestor?
(the situation when one DisplayObject covers another and both are on same DisplayList)
Or sth else:
Block a single event MouseEvent.CLICK or all except one
mouseEnabled=false;
allowedEvent=MouseEvent.MOUSE_MOVE; //functional example