Yesterday evening flying I found my radar giving me unusual references for example showing the bird behind me when it was clearly in front. Initially thought it could be due to using windsurfers and echo (misguided!). This morning, sitting stationary I noticed that the compass was pointing the opposite way. I calibrated, several times, in several locations. It is still showing between 90-45 degrees off. But I'm not getting any compass abnormality errors either... To make things worse, this reading is not consistent. Sitting in the middle of the lawn the compass rotates whilst stationary....Here's a quick film of the issue. I've flown multiple times successfully at this location. Middle of nowhere. Can anyone suggest a course of action? I can't be bothered with the fuss of warranty claim for a $15 compass replacement. In your judgement is this what I need to do?