3.5.0-rc8 FlipOver of our X8 during TakeOff

Hi, I hope this is the right category to get some help.

I do have pixhawk in use for some years now in several UAV`S, so no newbie.
We had a crash with a brandnew pixhawk 2.1 in a X8 Frame with DJI E1200pro Motors.

After more than 15 normal flights, the UAV flipped over during take off.
I armed the copter and directly after arming, the motors began to run at high throttle and the copter flipped over in flight direction.
Attached, two logfile of the last fine flight and the Crash file.
BIN files
Does anybody please have an idea what happened?
Thanks for any help!

I see full stick movement on pitch axis (RC channel 2) and corresponding pitch angle rizing. Maybe RC problems?