Bernard,
In a coordinated turn (with no sideslip)
what makes the plane stay in it's bank angle
is the deflection of the ailerons.
the inner wing has lower airfoil camber (lower CL) due to aileron up, and the outer wing has an increase in airfoil camber
due to aileron down (higher CL)

if you live the sticks while in a turn,
low c.g A/P will roll back while others like EXTRA 300 (middle c.g)
will stay in it's current bank angle.

please explain in a more scientific manner what is wrong
with my previous explanation.