Dynamic Response Spectrum Inputs not affecting natural frequency results

I am attempting to find the natural frequency of my staircase model as shown below using the total weight of the structure distributed evenly over every node as a nodal mass in the Ty direction. My issue is, I am able to get a frequency running the dynamic analysis but any changes made in the earthquake acceleration inputs has zero affect on the frequency results. I need to ensure that my damping is being taken into consideration but changing the scale factor and/or the damping percentage has not changed the frequency whatsoever. Any insight would be helpful as to why my inputs may not be being taken into consideration. Thank you.