The thread starter hasn't been online since 2018, so you might want to start a new thread.I know this is a super old post. Just wondering how this turned out if you are still on BYC. I have a chick showing the same signs.
Do you have a food scale that you can weigh it on? I like to weigh mine, especially when they seem a little off. Chicks should gain some weight every day, weighing them shows me how well they are doing.