Aux ports PWM when safety switch not engaged

Hello px4World,

I have made my own experimental airframe, which is based on a normal fixed wing, but instead of servo-actuated control surfaces, I am using small wingtip and tailtip motors. (It is not VTOL as the motors are only used for attitude control, not lift). I use the mixer files to achieve this.

In the current configuration I am testing, I have 4 motors controlled by the main.mix file, plugged into the main ports, and 4 controlled by the aux.mix file, plugged into the aux ports.

I have run into this problem: When the aircraft is unarmed, nothing spins. Good. When I arm the safety switch and arm using the transmitter, everything works great. However, when I disarm the safety switch, all the aux ports fire up. Very scary!
I’m guessing they spin up to 50%, as this would be neutral servo position? I can’t find out exactly, however, as the log stops when it disarms.

I have played around with PWM_AUX_DISARMED, but it doesn’t help.

Does anyone know what is causing this?

Thanks,
Patrick