I gave an auto mission of takeoff to a waypoint of 40m altitude, after 15 mins of video recording i initiated RTL it lands and then the motor does not stops and disarm, instead the motor gains some speed and the hex topples and crash disarms. even in the stabilize mode i cannot disarm through rc has zero throttle and left rudder it yaws aggressively instead of disarming This is 4th time in a day and now has become dangerous.
Firmware: hexacopter 3.6.9
this same happens in loiter and stabilize mode also after landing
NOTE: I HAVE TRIED THESE 3 MODES SO FAR.
NEED URGENT HELP WITH THIS