Yeah… this is a strange one. It does appear to be partially environmental, I measured a strong magnetic field coming from the electrical box. I noticed this earlier and moved the compass to avoid it. However, that did not work…nor did anything else I tried, which is when I about tore my hair out… BUT now, the problem suddenly vanished and the compass is rock solid… though only after trying things which I’ve tried before. I am thinking perhaps some changes required a reboot and I just happened to luckily reboot after making the correct change? lol
I will note that currently all 3 compasses are active, with the primary compass being unit 1, set to external. No directional offsets. Does that sound correct? Previously the 3rd compass was disabled - but that’s the odd thing, since there is so much magnetic interference inside the electrical box, I would have expected disabling the internal pixhawk compasses would have been beneficial. Anyway, once it started working I knocked on wood and left it be since I had a decent amount of work to do with it. It has about 10 hours on it now with no issues at all.
I’ll download some Dataflash logs later - the pixhawk is not in a very accessible location and the companion computer is not yet setup. I’ll be soon tearing into it to find what is creating that magnetic field. I am thinking/hoping some Chinese antenna extenders for an RDF900, because that is not working well either (can hardly download params or get location updates) where normally those are reasonably solid.
Will update soon! Thanks for the help/input.