Motor started after compass calibration

Hello, This is Nobu.
I was doing compass calibration. After that, motor was started suddenly.
It’s very scary…
But, before compass caliblration , I was doing Radio calibraltion.
Mission planner was conected. Status is disarm.
I understand that motor may start after Radio calibration.
But this case was after compass calibration .
Mission planner said disarm , so I have no logfile.
Does anyone know the reason of this motor starting.
I’m not good at English sorry…