Why is the program calibrated without a graph when running?

When I turn off the graph correction and turn off the headroom safe and set the volume to maximum, there should be no effect, but when I turn on the program, the sound changes. 

ai says that the sound can change when the routing is changed, so does this mean that it is not affected by the audio interface?

I can feel the sound change when the routing is changed. What is the effect?