Chick acting strange

I’ve had these 4 chicks since Easter. They’ve all been acting normally, but this one (I think is a Cream Legbar) is drinking fine, but she’s not eating, and she’s standing upright and peeping nonstop. She’s drinking by herself though. She had pasty butt for about 2 days before I cleaned it. I thought she would act normal after that, but she’s been like this for another 2 days, even after I cleaned her butt. She also doesn’t react to my hand, she huddles up against me and peeps. At first I thought it was malnutrition, so I gave her some olive oil with a pipette about 20 hours ago since it’s got a fat and calories. She still acting weird. I’m not sure what to do.