Linking Pixhawk to Alexmos 32bit Yaw Issue

Hello!

I’m building my first quad, and having had it 99% finished for months, the last Issue is bugging me like crazy.

I’m using a 3DR pixhawk, with an Alexmos 32Bit gimbal. I got the gimbal all calibrated so it stabilises nicely on its own, and connected the RCPitch/RCRoll/RC Yaw directly to the PWM on me receiver which worked great except the Yaw always wanted to face the same way, which is useless on a quadcopter.

I discovered if I wacked the response speed in “Follow Yaw” in SimpleBCU right up to 80, I could get it to follow much better, but still not keep up with the speed the quad turns at.
I felt it might do better if connected to the flight controller. So after alot of searching and no finding, I worked out (from the storm32 topic) how to connect my alexmos over UART. i changed the control inputs for P/R/Y (or pan they call it) to come from the FC, and removed the RC inputs. (Note I set Mount type to alexmos, rather than mavlink as described in the wiki)
Now I’m back in my original position, with Pitch and Roll stabilising beautifully, but Yaw insisting on facing the same way. I can’t find anyway to change it.

Is anyone familiar with connecting these two? can you recommend a guide I missed, or explain what setup you have that works? Or any suggestions for settings etc.

Many thanks!

Dave