Step away from the egg! LOL
My egg started pipping on Sunday right after lock down But I am not expecting them to hatch until Wednesday.
If I'm right (Im new to this too but I have read everything I can) and my eggs are based on this too between internal and external pip it can be up to nearly two days. From the external pip to hatch it can be anything up to 72 hours on top of that. It sounds like your duckling is right on form.
I'm finding they do a bit of taping and then rest up. It sounds like you have a very good chance with this one as long as you do NOT open the incubator. Leave well alone even when his head pops out. It takes a hell of a lot of effort so it needs to keep resting up. It could be another day before he is free. The biggest mistake seems to be our impatience. Each of those stage makes baby stronger and he has to sleep in between. So when he breaks out he will sleep. Don't think he has died and open the incubator up.
Don't give up on him yet. You made the mistake with the other two now you have another chance. Let nature do what she has done from time began. She knows how this goes. And so does the duckling. The humidity will be fine as I'm finding it rises on its own as they go along so as long as you leave well alone he won't shrink wrap.
Now you need to let this run it's own course how ever hard that is. The duckling has a strong will to live and you need to honour that. Sit back and just watch and listen.
Good luck x
Agree up to a certain point, call ducks need assistance at times, so it would depend on the type if duck you are trying to hatch that will make all the difference..