I have the same problem with my 2014 F-150 STX SuperCrew 4x4 and I've done everything to try and get my sync working again and again.

Step one was pulling the fuse behind the passenger kick panel. I tried that at least 3 times.

Step two was disconnect the battery for a 10-15 minute time period, did that about 3 times as well.

Step three was master reset, did that several times with no success.

Step four was see my local dealer. Their solution was my phone's Bluetooth was the problem. Impossible because my Galaxy S5 was the only phone I used since bought the truck new in February 2015. To remedy this, I bought the latest and greatest from Samsung, a Galaxy S8+, and still no sync audio streaming, aux-in, USB input, or voice commands.

Step five was return to my local dealer with a new phone. They wanted to charge $1900 to replace the radio, the sync unit, steering wheel, and some other components.

It's a great truck but it's quickly getting a bad rap because of the sync not working at all. I have turned several people away from buying a Ford because of this sole problem. Word of mouth truly is the best or worst marketing a company can have. I'd like a solution that doesn't involve taking out a small loan.