Issue 4-motors tiltrotor

Hello ,

I write this because the past week I had a problem with the transition that made the plane crash. When the transition speed was reached, the plane pitched up hard making a loop and started falling. At the beginning it looked as if it was able to recover, but finally it felt to the ground.

I summarize some things that I found in the log that seem strange to me:
-When the transition airspeed was reached, all the four motors started to running with the same output, regardless the transition time was settled to 30 seconds.
-The output of the four motors rised over the limit (thr_max), that was 85%, when the transition airspeed was reached.
-The vibrations and the compasses look right to me.
-One of the motors was saturated (rear left motor) and when the transition speed was reached, it decreased instantly to match the output of the other motors.

I attach the log.

I will apprecite if someone can have a look at it and give me some opinion or advice and if something is working wrong.
It has never been flown as a plane before.

Thank you and regards,
Isaac Martinez Garcia