VTOL transition to hover airspeed increase

Hi,
I have a tiltrotor-tri. Flying quite well but when transitioning back to hover the front 2 motors go to high power while still pointing mostly forward, causing a large speed increase. Is there a setting to feed in the hover power more steadily? I have already increased the speed that the motors tilt to vertical but the issue is still there. The red line is airspeed, the others, 3 motor PWM.
Thanks