Compass problem

hi guys … i’m trying to run an antenna tracker with omnibusf4 v3 (mounted on pitch) and bn880 (mounted on pan axis), a continuous rotation servo for the pan and a 90degree for pitch. I connected the pc to the tracker via bluetooth and I am simulating the operation with sitl with airplane. the tracker works, moves in the right direction but after a while it seems to be lagging behind the plane. I did several tests and the problem seems to be the compass … the calibration was successful and at power on it marks the right direction. after two minutes of tracking I checked and the compass on the planner has about 70 degrees of difference from the real position, but no error is transmitted. What could it be? ardutacker 1.2 dev

Is it gyro drift being factored into the rotation equation? Maybe turn off any EKF methods so that it might just use the compass. I think this is possible, but I am a bit of a beginner with Ardupilot.