One time my F150 COMPASS quit working and after going through the books etc I figured out the problem was I had recently added a hanging Indian Dream Catcher on my rear view mirror. This is where the compass head is located that plugs into the truck computer on my truck...
I re-situated the loop around the rear mirror and all started working again...
Probably not your problem but submitted what I did...
I'm guessing the dream catcher was also capturing the compass signal????
Maybe a quick call to FORD Shop manager for some ideas...
Roy Ken