First time hatching. The eggs came from my own birds and were put in the incubator the same day they were laid. I started with 18. One never developed anything and 4 hatched between day 22 and 24. Two of the chicks below had pipped external and one of those had started zipping but only made it about 1/3 of the way. Another one had pipped internal but not external. Another one looked fully developed but never pipped. Humidity was running around 66% and temps between 37 and 37.5 C on lockdown. Anyone have any thoughts as to what went wrong? TIA!