Out of my 14 shipped eggs so far 4 are living don't know if all are going to make it but I have my fingers crossed. They seem to be getting a little spunk. I lost my calico's, mottled, and 1 silver laced that I was really hoping hatched.I hope that I got a rooster I have 2 female cochins had 3 but hawk just recently killed one. The other 13 eggs were my sister in law from her chickens so not shipped other than the drive to my house and some of them did same thing, 4 waiting on 2 have heads out and 1 of them my chick pecked at and I see yellow liquid inside don't think it's gonna make it very weak. And 2 still pipping. The rest died right before or during lockdown. I have my own duck eggs in due next week I'll see how that turns out. Was debating on whether to turn off fan or keep in on during lockdown to see if that does anything different.
I think you are supposed to turn off the fan at lockdown. I think leaving it on will dry out the membranes. If you incubate and hatch in the same box, you can put a switch on the fan and just turn it on and off like a lightbulb, if you know how to do such a thing. My husband installed on on my incubating box so if I want to use it as a hatcher I can turn the fan off. Mohillbilly said you should turn the fan off to turn the eggs and I thought that was good idea. Seems like it would help keep the humidity and air more still while you're in there working. I kept forgetting to do it and this time around I am not turning eggs by hand, rather I am tilting the entire box on a thick book to keep air cells as stable as I possibly can while trying to keep the chick from sticking to the sides. It sounds like you will have to open them up as soon as you are able and try to investigate what went wrong. I find that tricky to understand when they are alive at lockdown and then die
what exactly they died from. Everything I read said it was a humidity issue: too low, too high. That really helped, LOL!