Just had an A.R.E. Cap installed on our truck. We now have a flappy noise. Faster we go more it flaps. Cap seems solid and dealer won’t help. Says it’s not from the cap. It definitely started when cap was installed. Truck is a 2016 Ford F150 xl. Cap is a high rise. Seems to have some ozzing around the window which I wonder if the window is causing the noise. Any one have any ideas?