RC passthrough on AUX5 for simple switch actuated servo

I am flying a custom VTOL Tiltrotor on an Orange Cube (modified PX4 v1.11). The 4 tilt servos are hooked up to the first 4 AUX PWM outputs. I want to add a simple two position servo on AUX5. In my airframe file I have added AUX5 as a PWM output and then in QGC I did RC_MAP_AUX5 = Channel 9 (servo channel). In the radio config tab I can see the channel 9 slider moving when the button is pressed. The servo however, is unresponsive (confirmed that is has power). Not sure what else I may have to change in the PX4 code to make this servo work, any help is appreciated.

Do I need to set up a mixer for this AUX? If so, what group/index would I need for the output?