I'm doing nutri-drench, a stabilizing chair(made from an egg carton, paper towel and vet wrap) and yoke-water mixture. My last ones I had like this where from my Halloween hatch. Two of the Sebrights had issues like this.I treated a star gazer a couple years ago. It's just a vitamin deficiency.
I believe I mixed minced garlic, raw honey, and apple cider vinegar.
That healed up the chick in 2 days I believe?
There's homeopathic/natural ways to treat it, that actually work really well.