[Sloved]Compass issue about copter3.4.4

ArduCopter Copter 3.4
1

hi all,
I just updated my cuav pixhack to copter3.4.4 firmware and discovered the mag EKF was abnormally when flying.
I had tried to re-calibration compass, but no luck.
The mag issue does not occur in firmware 3.4.2.
How can I solve it? Any advise is welcome~
Thanks

screenshot2.JPG1281×349 42.1 KB

screenshot.JPG689×536 44.6 KB

LOG: 55.zip (2.3 MB)

Mag in firmware 3.4.2 is good

screenshot342.JPG1406×373 43.2 KB

2

More info:
MAG1 is extenal M8N GPS and HMC5983 compass,
MAG2 is pixhack internal compass.

MAG2 result looks good, extenal compass looks abnormally, but both running good in firmware copter 3.4.2

3

Sloved!
The root cause is the battery had come adrift from the GPS module.