Pixhawk 2.1 compass problem

Im using the Pixhawk 2.1 with ArduPlane V3.8.4 (e62e40a5) firmware.

I have problems with Pixhawk 2.1 compasses, so the Mission planner is saying “Error compass variance” and disallow me from Arming normally.

The compasses calibration values are:

And after board reboot I see following picture when the plane hold still, the real heading I drew with red dashed line.

When plane is turned at the same location, EKF-compass status becames RED and is jumping from 0.5 - 1.0 and “Error Compass Variance” error message appear on HUD.