I think the video would play better on this site if you would post it to YouTube first, then paste the link here. Twitter is worthless, in my highfalutin opinion, and frankly is a waste of time.
Are these chicks under a heat source still? What are they in? How many of them are there and what is the size of the container or pen? What is the bedding?
Have you pried open the beak of this chick and looked in her throat? Ears? Is there any gunk in the ears or throat or nares?
What is her behavior? What does her poop look like? Is she eating?