Yesterday, I went to the same location I had the yaw error. I placed the NEO on my folded up landing pad that was located on the ice just out from the beach and checked the direction of the AC on the map and noticed that it was facing opposite the actual orientation of the NEO. I shut down and moved down the ice a bit and the same thing. I did not take off so there is no log to upload. I did not have my rechargeable handwarmers and there were no other source of magnets nearby. The only thing I can think of is there was some sort of magnetic disturbance under the ice. In that location the water would have been only a few centimetres deep.
Chris
Chris