Define motion zones screen missing 1/3 of my cam view

I have a stick-up cam on my front porch. When I look at the view through the cam, I can see my entire porch, but when I go into the screen to define motion zones, the view I see is missing the upper 1/3 of the view which is exactly where I need to define the motion zones. Can someone please help me understand why this is happening? Is there a setting somewhere that's causing this?