My 2017 enclave has a shake/shimmy when accelerating from 45mph up to 60mph and it only does it while accelerating. I bought the car new and it has around 6,300 miles on it now. The dealer has balanced the tires two times, checked the alignment, checked everything and has not found the cause. When I had around 400 to 500 miles on it we were running around 60mph and heard a noise that sounded like something broke and the problem started around that time. Have there been other reports of this problem?