My 2015 6.2/8 speed had this problem. I complained about it to the dealership for 6 months. They kept trying to tell me it was a tire problem and that it would only go away if I got away from AT tires. Finally, on the 4th visit to the dealership, they flushed the transmission and replaced the torque converter. Problem solved. The tech said he didn't know what the actual problem was but could definitely tell something was "off" in the torque converter. That was about 4 months ago, no issues since then.