Sometimes if I make a change to the camera settings or resolution it will affect the motion detection zone. I do get a pop up telling me something vague to the effect of "some settings may be changed due to this action". A few times during my routine audits I've discovered the motion zone is altered or shrunk and I have to redo it. Most end users wouldn't be aware of this and might have their motion zones messed up to the point of being useless.
My assessment of OnGuard is that while it's definitely not user friendly, it's pretty good when it's working properly.
The problem is that due to the constant "little" issues that crop up all the time the system needs constant attention. Changes made here affect it over there, and the changes to fix that issue affected another issue over there. It's a constant reciprocation of issues, each predicated on the previous problem.