I have been flying waypoint missions with just four points all at 50m and then looping the mission with Do_Jump. The mission flies perfectly but the plane altimeter does not fly at 50m. The altimeter is reading 20-35m during the mission. When I try to type a number into the change altitude window like 100m it flies up to round 80m. Does anyone know why it is not trying to hit the correct altitude? I know that altimeters can drift but I would still think that if the altimeter is wrong then the plane would try to fly at the set elevation but it would physically be higher or lower then requested due to the error. Seems to get worse over time as well (am flying over fire fronts for around 40mins). I have also tried pulling up during missions but as soon as I let go of the stick it returns back down to lower elevations. Very strange.