In using nav this past winter had several problems. Very often it would take me to destination but have me go past address and tell me to make u-turn, also while in route would tell to take a turn at an intersection and then say make u-turn and go back to original road I just turned off . When using POI would tell me I was too close for directions but destination was actually up to 100 miles away. At times vehicle indicator on map would be well off road I was on. Several times road would end in nowhere. Truck is great at this point nav sucks. Dealer said to bring in and they would look at but did not sound very positive about fixing maybe I can get something here to help. Trip was about 12000 miles puling 40' trailer so u-turns are a problem, Thanks

 

I don't know if your system is the same as my Taurus, but there was an update for the GPS module to fix issues with location.

I've also heard of some people having problems with the navigation while towing a trailer. I think the antenna is on the back of the cab, and if the trailer is high enough it causes problems?