Bring it for service. The symptoms you’re describing are a faulty differential.I just got back from driving it around in circles in a parking lot for half an hour. I’m more stumped now than before.
At take off, almost exclusively when turning left, it will buck and shake from the rear. It happens sometimes in normal or eco, almost every time in sport. When turning tight circles, there is a constant rubbing sound from under the car.
This may be two different things or somehow connected.