VehicleMagnetometer uORB message

Hi, When does the calibration_count change for the uORB message VehicleMagnetometer (VehicleMagnetometer (UORB message) | PX4 Guide (main)) ? From what I understand, it should be updated and published when you calibrate the compass? But what I am facing, is on fmu-v6c, is that it only publishes it once when calibrating the compass for the first time after board reset. And the calibration count only updates to 3.
Could someone clarify this to me?