M300 flies at incorrect ATL and AGL

Hi there,

Yesterday I attempted to plan and fly a mission using our M300 and P1 and Altum (Dual gimbal mount). The mission height was set to 80m and I opted to use terrain following. The graph elevations and heights were checked and were correct prior to flight. The drone however attempted to fly the mission at 20m ATL/AGL. The drone also started the mission by flying backwards and then spinning around to fly forwards after approximately 10 seconds into the mission. I shut down everything, replanned the mission from scratch and unfortunately encountered the same result. The offset was set to 0m.

I replanned the mission for 100m and then the drone attempted to fly the mission at 40m ATL/AGL. The drone height did vary with the terrain however it was consistently 60m lower than the planned height.