Build OK, upload OK, link Ok but unable to arm

I have built master firmware source px4-v2_default into IRIS+ with no errors
After reboot, parameters are read ok. I can calibrate accels and others but COMPASS is ‘grayed’ in the Mission Planner. is there any step I am missing? Is there an IRIS+ config table I have to load?
(Needless to day that recovering the original binary everything is ok, so no hardware failures are likely)
Warm regards
Jesús G

If you’re using PX4 firmware, you should be using QGroundControl, not Mission Planner, to calibrate sensors.