Changing the yield strength should change the design unless one of the following is happening in your case
1. The FYLD parameter is being defined after the CHECK CODE command in the input editor.
2. The critical condition for the design is something that is independent of steel strength for example slenderness.
I have attached a sample model for your reference where the design ratio is changing with FYLD.
I noted that for this code, critical condition ( clause) and critical load case is not being reported in the analysis output file or the table by default. I will log this enhancement to be taken up in future. For now, here is a workaround. Specify the TRACK parameter and set it to 1 for the design and you will get both critical condition and load case reported in the analysis output file.
(Please visit the site to view this file)