YAW very sluggish

I have two Vtol planes (one with tail and one as delta wing) with two front tilting motor and one in the back for the vtol.

Everything seems to be fine, transitions and normal flight, the only issue I don’t know how to fix at this stage is a very sluggish yaw control on vtol mode (qstabilize).

the model wants to yaw and when I correct with the stick it takes several seconds before actually stop rotation and follow the stick… with the consequence of overshooting and rotate way over after release the stick. what should I try to adjust in the parameter to improve responsiveness (only for vectored yaw).

Thanks for your help guys…