Ublox NEO-M8N Compass not detected

I have a Ublox NEO-M8N module connected to my Pixhawk on the GPS and I2C ports. The pixhawk runs firmware 3.2.1.
The GPS works perfect, but the compass is not detected by the Pixhawk. After initialisation, the COMPASS_EXTERNAL parameter is 0.
I did a simple test: powered on, in Mission Planner, moving the frame changes the orientation in the Flight Data Screen; moving the GPS unit alone, doesn’t.

Anyone else had this problem? What other tests can I run to see if my external compass is working?

Many thanks!

As it turns out, it was the cable. Or the DF13 connector.
Fixed now, but it made me feel stupid for a while.

Hey thepeter, could you tell me what setup configs. you used for the Pixhawk FW 3.2.1. I am having an issue with “conflicting compass information” and I am also using the NEO-M8N (GPS/I2C conn. to Pixhawk).