Little water in base not on top. leaves may turn yellow, as they do pull them off at the corm, same with the flowers. Give a little drop of water for a while every other day - they do not need that much water, but I think that does
As part of life cycle they will die back, seen by leaves dying back, but will quickly rejuvenate, When leaves have died back water sparingly, un til you see new growth - oh, and only feed - half strength Baby Bio is fine - when the re are noe flowers or buds. Hope this makes sense
extra - do not keep near radiator preferbly on a N facing window.
Come back and ask more if you need to. have kept them for years