Help second chicken to look like this

[MASGPoultry]

My broiler Ross breed is 26 days old is looking sick, it's the second one to exhibit this type of symptoms. the first one was like this for about a week before it died from what seemed to be a heart attack since it rapidly flapped its wings twisted its neck and died in my arms. It also had weak looking legs and they looked pale, the day it died it couldn't stand and lied on its side and the crop felt empty
This one I noticed yesterday, it stand at one place for a long time, it's feathers are fluffed up and it's neck is drawn in. It seems to eat but it's crop is also empty. It allso shakes it's head while making this sound like a hiccup I've quarantined it but I'm worried since it's happening for the second time. It's poop looks normal please help I'm super worried

 

[CaradineCousins]

I'm sorry no one is responding, i have no words of advice to offer. I really hope it gets better. I hope someone responds soon.