Good question. This latest update changed lots of things in motion detection. When you open up the "Edit motion zones", Zone A comes up first. It is the old single zone motion detection, except that now the blocked area is clear, and the triggering area is green. What I do is use invert, then add an area to exclude, then invert again. The areas I want motion blocked are now clear, and the unblocked area is green.
The new zones I think of as trigger areas for alarms, and have not tried to use them as yet.