It is normal. Some of my amaryllis has no leaves right now. It comes back better towards Spring. Just let it continue on receiving as much bright light so the remaining green leaves can return more energy to the bulb for its future growing needs. Remove all the yellowed ones to make it cleaner.
I also take this time once all the leaves are gone, to gently remove those older bulb sheaths, they are like onions anyways, lots of cover.
