It happens when I go full throttle and then start to ease off of throttle approaching redline. Or, it is also happening if I try to hold the RPM's at about 5k or so and lightly modulate the throttle. Very annoying, and a bit dangerous when I was in the long sweeping turns 8 and 9.
Video is up from one of the earlier sessiosn that day:
https://youtu.be/79K8W73SZ24