Not familiar with the type of bator. Are youthinking the humidity was too high or too low? Is it stil air or forced? What temp was it ran at?
Do you have a hygrometer to measure your humidity? Or does the incubator have a built in one. I shoot for 45% day 1-18 then 65% for lockdown. The humidity needs to be an average over the entire incubation period. Short term variations should not be a problem as long as your average has been ok and the eggs have lost enough moisture in order for the air sacs to grow large enough for the chick to pip into. Too much humidity and the air sac may not grow enough and have too much moisture when the chick pips it could drown. It may not just be humidity have your temps been ok? Have you double checked with another thermometer that it's running at the correct temp. Some say factory set but they are not. Have you had all vents open so the eggs get as much oxygen as possible? Do you have auto turn? If hand turning should be 3 times per day but 5 is better. We're these eggs posted to you? Posted eggs have a lower hatch rate due to being roughly handled. This is a great article on hatching with lots of other links to great info https://www.backyardchickens.com/a/hatching-eggs-101
