PWM Spike on startup

ArduPlane Plane 3.3
1

I am using an IR trigger for a camera for photogrammetry, however, when I first plug the pixhawk in it gives a high PWM spike which in turn triggers the IR sensor to put the camera in record mode. This is a big problem and should not happen.

What am I doing wrong, or, why on startup is the pixhawk sending a high PWM pulse to the RC9 channel?

APM Plane 3.3.0

2

Strange part is RC9 and higher gives a high PWM Spike on startup, while, RC8 and lower gives a low PWM Spike.

This is good news though as our camera trigger on RC8 or lower now only takes a picture instead of putting the camera into record mode, so, no more problems.