Channel 1 always active - even with safety switch

Why is it that my Channel 1 aileron is always on no matter if the safety switch is activated or not? I’m running a Pixhawk 2.1. The rest of the channels work as expected, but channel 1 is always on. It’s annoying especially if I switch my transmitter off and the plane triggers RTL because of failsafe.

Safety switch disable motor arming it is normal that without the radio signal the plane goes in failsafe mode and move ailerons.

I had disable safety switch and without radio signal the behavior is the same.

I understand what the safety switch does. All other channels are disabled including my channel 5 which is also set to the same function as channel 1 for the other wing. ONLY the channel 1 servo is active and receiving PWM when the safety switch is on safe mode - not the rest. Why is that?