Interesting. Maybe the thicker shells are their way of compensating for the dry conditions. Thicker shells do lose moisture slower during incubation, so that makes sense. Thanks!
Could be with the dry nature of your climate, the hens have naturally adapted to it! So normal incubation needs to more closely mimic nature.
I’m curious if the egg shells are thin, thick, porous, heavy bloom? Anything odd about them?
Congrats on working it out though, incubating is always a...