I have three Brinsea incubators running right now. On lockdown day, I move the eggs to styrofoam hatchers to keep the Brinseas clean. The eggs from one of them hatches out on day 21 like clock work. The eggs from the second one (Octagon 40 Eco), start hatching on the evening of day 19, and are usually all hatched by the afternoon of day 20. The eggs from the other incubator in question (Octagon 20 Advance) don't ever hatch until day 23-34. My question is... if everything is in the same room, basically right next to each other, and I'm hatching the same breeds of eggs, from our own flock, in the same brand of incubators...why the discrepancies?