Went and picked up my 2018 721 today from dealer. Started back home and the first 70 or so miles was fine. Them miles were 65 mph max. Then I get to the main interstate and start hitting higher speeds like 70 to 73. Well from 67 to 71 I can feel a pretty bad vibration from the trailer. It stops at 66 mph down and stops at 72 mph higher. I stop a couple times to check wheels for heat and loose lug nuts but all is well. I get the boat home (4.5 hours from dealer) and start looking around. My brake rotors, all 4 of them are eat up, like ditches dug in them. So I'm calling Marine Master in the morning to tell them and get new parts sent to me but what could have caused this???