Still doing okay? If you wait too long to help a 'stuck' chick, they tend to have issues gaining mobility, but this usually clears up within the first week.
Was there anything strange about this chick's development pre-hatch? Do you know if the parent stock were heavily inbred? Fluctuations in temperature, nutrition deficiency in parent stock, mishandling of eggs (in shipped eggs), setting fairy eggs... So many things that can result in a deformed or poor performing chick.
It sounds lucky to have not had congenital issues that did it in before now.