Copter not following terrain in AUTO mode on the way to 1st Waypoint

Hi Ardu Community

I have faced a very peculiar issue. While flying a copter with terrain follow and terrain enable set to 1, using the SRTM data, my copter crashed into the terrain while on the way to 1st waypoint. First Way Point was 1.5 km away from home location, with a hill’s ascent and descent along the way, but the drone did not follow the terrain and collided into the hill 330m away from home at a height of 70m.

I am attaching the crash logs below for your analysis and suggestions. Kindly help me out in identifying the root cause.

Crash Log

@rmackay9 @tridge looking forward to your analysis