I got to see the reason of my problem:
I was using Manual mode of a VTOL.
In Manual mode of Fixed Wing status of a VTOL, the control surfaces does not work automatically by attitude controller, but it works by RC sticks.
In Fixed Wing status in a VTOL, Manual mode and Stabilized mode are different each other.
But I thought they are same since I was too accustomed to multicopters because in multicopters, Manual mode means Stabilized mode.