Sudden oscillations on large X8 in loiter

Hi all,

We were out flying out today when the drone started rolling left to right and vice versa uncontrolled. The pilot had no input, however we did manage to save the drone by switching out from loiter (into Auto accidentally, but we switched to loiter after and landed fine). After checking the drone over, we took off again and flew for another 30 mins or so without issue.
I’ve had a look through the logs but I can’t seem to find an obvious explanation for the cause. I would appreciate if anyone had any thoughts on this.

The log file:

The drone frame is a Gryphon X8, running a pixhawk cube black. Motors are T-Motor u8 lite 100KV, props are T-Motor 29.2 x 9.5. It was slightly windy today (10-12mph winds occasionally).

Anyone? Any help would be greatly appreciated! Thanks

That’s weird. However is a perfect sine wave of oscillation

Same thing with your Battery and Current

What I do actually find odd is your Magnometers…

I believe the Cube has two onboard.

Both of them freaked out about the time of your incident as shown here:

But your third compass is reporting very little issues:

What is your compass arrangement?

Thank you for your reply!
It’s very strange, GPS and baro seem fine. No strange spikes which could’ve thrown off the FC. And we managed to stabilise it by changing flight modes.
I’ve disabled the 2 internal compasses on the cube and I’m using an external compass on the Here2 GPS which is mounted clear of the frame. Am I correct in saying the internal compass variation is expected as the large current fluctuations would cause the changing magnetic field?

Have the 2 internals always been disabled?

Yes, the internal compasses have high interference due to the Cubes position in the frame so I disabled them from the start.