iphone 6 call waiting switches initial call off sync in car

I have had my 2014 Ford Escape for just over a year and within the last few weeks when I am on a call using sync an incoming call (call waiting) switches the initial call from sync to phone sometimes before I can hit ignore sometimes after I hit ignore. I then have to go to my phone, tough the green active initial call and switch back to sync. I do not know why this is happening. I have not changed any settings. I updated to iOS 8.3...not sure if I did that before or after the problem started. This is very frustrating as I am driving so its difficult to look at my phone to switch the initial call back to sync and its frustrating that this happens just in general. Has anyone has the same issue or know how to fix it?! thanks!!