When am is armed my generic wing plane in manual mode the throttle motor was rotation

am using pixhawk4 . i am using virtual joystick in manual mode . when am armed the vehicle the throttle motor was rotating in 5% throttle . when using virtually throttle increase it is increasing .

at the same time am using in autopilot mode also on that time start the mission. on that time also the throttle motor was rotating and when am apply force to throw the plane throttle motor was increasing the throttle speed .