I have zero experience with these but if u moved into a smaller in closed space wouldn’t your humidity be easier to keep constant? I have one of the humidity readers that tells u the high and low for the day as well as the high and low for the temps. I got it at Walmart for $10. Have u tried that to see what’s happening thought the day?
Also I wouldn’t be scared to try a chick to see if it sparks something inside her to eat again
regardless good luck!!