Had bunion surgery 8 months ago. is it normal to have pain when going down the stairs or walking more than 20 minutes? had a 2nd surgery to fix 1st

Not expected: You didn’t say what was repaired on 2nd surgery, regardless, pain is not an expected outcome of this common surgery. It is possible that a small fracture is present, a nerve entrapment, residual bone chip, or deep infection. See your surgeon or a different one to fully examine why the problem continues, and (hopefully) get this corrected. Good luck