Spirit System

After trying to get my "coaxial" to work without drifting, I noticed that two of the cyclic servos made small movements when ever I engaged coaxial by a switch. They go back to "normal" when I switch the coaxial off. This is with the heli stationary on the bench with system energized but motor not running. What are these servo reacting to? They move as reflected in the drift I have been trying to eliminate - bit backward and a bit to the left.
Dazed and confused.
Thanks, Thomas

Hello,

servos are moving according horizont. It is sensed by motion sensors. So any model tilt at the ground will result in this deviation. This is normal behavior.

Thank you for responding. So, Heli should be as level as possible when performing setup. After setup, should heli be level when being plugged in to battery before flight? When is it determining the correct horizon?
Trying to thoroughly understand.
Thanks again.