Help! VTOL motors stopping In the mid flight

ArduPlane VTOL Plane
1

I am having a problem with the VTOL motors of my Quadplane. The back motor tends to drop abruptly in the air, resulting in the plane becoming unstable (and sometimes crashing). This has happened several times, even after I replaced the motors in the rear. I don’t know what is causing this issue and how to fix it.
I would appreciate any help or advice from anyone who has experienced this before. Thank you for your time and attention.

You can check the log and video of the flight in the link below.
Video & Log

Pitch DIP
Pitch DIP1671×915 18.3 KB

Video & Log

2

@kannanrj can I know why you limited the servo 5 output of your rear motor to 1900 and min as 1100.

3

Thank you for your kind reply.

I applied the Servo 5 output to the right tilt motor and adjusted the minimum and maximum PWM values with the QESC calibration.

Please accept my apologies for the delayed response.