After takeoff airplane turns and starting to decend on Auto mode,,, it soppose to go to waypoint

I set mission, it takes off on automission, then turns direction to waypoint but decending , when it is close to ground i switched to FBWA and took the control, but it suppose to go to waypoint which is at 50 m altitude.

log here

just took a quick glance at it.
Throttle range does not look like calibrated. during initial climb throut is 127, and 99 on auto.
your min/max AS is 15…20m/s , yet IAS is very often way below, try to disable airspeed-use and verify IAS vs GS while flying around in stabilize, or increase power.