Car Will Not Start problems of the 2017 Lincoln MKX

We had taken our Lincoln for warranty work on the navigation/stereo and it was determined a part needed to be ordered. We were told we could drive the car while waiting on the part to arrive but when we went to pick it up our car would not start. The dealership charged the battery and ran it through some tests and everything checked out so we picked it up the next day. One day later the vehicle once again would not start. Dealership once again charged battery and ran it through tests and once again everything checked out. We decided to leave the vehicle at the dealership until the part for the navigation/stereo was replaced and then picked it up. We drove it about a week with absolutely no problems until I was pulling out of a parking lot into a street and my car lost all power including steering without any warning. I managed to coast into a single lane so I wasnt blocking the entire street. My car would not restart giving a message about power failure or power off on the display. I tried restarting several times while sitting blocking traffic including taking the key fob out of the car completely for a few minutes then placing it back in the car hoping something would reset and still had no luck. A tow truck arrived and towed my Lincoln into the dealership where it started right up so no code could be found. The dealership has no way to fix the issue without codes. I feel lucky this problem has only occured in relatively calm traffic and not while I was on the interstate where this issue could be deadly.