VTOL Plane. Altitude of quadplane increased in Q-Assist mode without any height change command

During flight, my quadplane faced issue of airspeed drop multiple time. Bird recovered using quad assit 2 x times. However at third instance (LOG time 16:41:03) an unusual behavior was observed. i.e. fixed wing propulsion motor throttle dropped to zero, while VTOL motors were ON due to q-assist, the quad plane gained height up to 1900 m from 1500m without any height change command.

it caused VTOL battery to deplete and during landing it fell down from height of 10 meters.

@tridge @Target0815 @Eosbandi @trimtuxworth @pompecukor @james_pattison

Log in link => 2025-04-01 15-03-54.bin - Google Drive

Questions are:

  1. Why Airspeed of quad plane dropped at multiple instances that triggered Q-Assist.
  2. In LOG time 16:41:03, Why fixed wing throttle dropped to zero while bird was in q-assist mode and plane gained height while using vtol motors, without any height change command.