I am looking to find out why my 10 chicks fully developed and did not hatch the other 32 did. They were all in a hobavator1602N with a fan and and eleftronic thermomeater and hygrometer. Humidity was 40% for first 18 days and 65%ish for last 3. 32 hatched fine. i opened the ones that did not hatch and air cells looked good for size. but chicks never broke in to them. Nor did they pip. but they were dead. Looked fully developed not to wet or dry. What are your thoughts?