During a turn, the VTOL fixed-wing aircraft suddenly flipped and crashed. This is a quadcopter layout VTOL fixed-wing aircraft, which had been flying well for dozens of flights. On the 28th flight, I was flying in FBWA mode. During a turn, the aircraft suddenly lost control and flipped over. Although the rotor motors were also spinning and trying to correct the attitude, they could not return the aircraft to normal flight, and it eventually crashed. I checked the data through the logs on the flight controller but couldn’t find any signs or reasons for the accident. I could only see that the attitude was already out of control before the crash. I really want to know why this happened. 
FlightLog: