Terrain follow problem with 1.3.51

Terrain following works perfectly with my plane (using Pixhawk) and I always check the altitude in right-click Map Tools/ Elevation Graph to make sure I haven’t made an error setting the altitude at each waypoint.

After upgrading to 1.3.51 this didn’t work at all and showed my altitude above and below the ground in a seemingly random altitude pattern.

I made a new simple 10 waypoint route all 50m above ground in terrain follow mode and the same thing - sometimes it showed my altitude below ground and sometimes above at random altitudes instead of a contant 50m above ground level.

I deleted 1.3.51 and reloaded 1.3.50 and this was back to normal and working fine.

Is it a bug?

make sure your home alt is set correctly. that’s the most likerly cause of an altitude shift.