Sometimes the oral prednisone (or other ways to inject or take steroids) helps. Sometimes it doesn't. Sometimes it helps with this particular exacerbation, and won't "work" next time. Sometimes it seems to help right away; other times the effects won't "kick in" for several days after you've started.
What "milder MS symptoms" were you hoping the steroids would help?
...I am not a doctor, nor health professional, and don't pretend to be one, here.....