Quadplane failing to take transition

I tried to fly Quadplane in AUTO mode. It was running fine before. But after several tries, suddenly it failed to transition from VTOL to plane mode. The pusher motor seemed to be running and the drone was trying to transition but eventually it came to a halt and didn’t move further. You can see it in video here.

As you can see that, the quadplane tries to transition just after takeoff but fails to do so. In another attempt, the quadplane did up and down motions (like hopping) in the air being unable to move forward.

Flight Log of this flight is attached below.
२०२०-०३-२० १६-२६-३८.tlog (259.6 KB)