I have a 2013 Focus ST with the MyTouch screen and Sync and I have a iphone 6s. For some time I experienced odd bluetooth connection issues between the iPhone and Sync where it would play for a bit then quit and a bunch of other annoying things. Recently I updated my iPhone to iOS 10 and so far the bluetooth connection has been reliable. This is just an observation so I'm not saying updating iOS will fix whatever bluetooth/Sync issues you're having but it seems to have helped my situation out.