Problems about PID tuning in Simscape Multibody

Hi, I'm trying to implement a PID control of an inverted pendulum system; the system has been modeled in Simscape Multibody.

I noticed that when I change the damping coefficient of revolute joint, the output is the same without changing PID gains unlike what I think it should be. For experience, I think that when the damping coefficient increases, the output should be slower. Why doesn't this happen?