I have the same problem! The system has a mind of its own. It's so random, I can't even describe. Ford has a major quality problem on their hands. I heard they fell 10 positions in the JD Powers quality study. Sync is sinking them!!
I would love to have only a pairing problem. Mine locks up so much that I keep a wrench in the glove box to pop the battery terminal! When it locks I no HVAC control, music ot GPS. It's not what I paid for. At this point, it’s affecting my mental and physical health. My blood pressure rises every time I enter the vehicle.
My 2012 Ford Edge is the big joke with my family, friends and co-workers. My Sync frequently locks up, I have to pull over, turn off the car and open door. I’m living the old “if Microsoft made cars” joke.