I have a 2020 C400 GT with 1200km. The Bybre front brake lever can squish any finger left behind it under moderate to heavy braking. Front brake lever travels an inch to and inch and a half before braking action. A buzzing sound from the front brake discs, under front braking use. Dealer has bled brakes, then replaced front brake master cylinder ... did not correct situation. They seem to be giving up on this problem. Any advice would be appreciated.