Changing yield strength of steel, but the results did not change in STAAD Pro v8i (Ver. 20.07.11.70)

Hi there, 

I did an analysis with default material properties. Then I tried to change the yield strength of steel from 36 ksi to 46 ksi to improve the performance of the beam, but the results did not change. It's strange. The version I used is 20.07.11.70. Thanks for your help. 

CR PS5.std