It seems that after the first flight plan, my copter goes into reversed altitude control. First loiter of the day, Perfect. First Flight plan of the day, perfect. Everything after that (after resets and battery changes maybe not flight plan changes) is crazy. I plotted pressures, relative alt and VFR hud altitude. See how the craft thinks it's 60 meters underground? See how, after the first flight plan, the altitudes reverse?
Is it because I'm in the Eastern Hemisphere? Anyone wanna help me solve this mystery?