I set 39 eggs in two incubators, divided by size. I'm keeping a written log of all the weights and other pertinent info on all the eggs. All eggs in the same incubator as #7 ranged from 63-67 grams when I set them. So if it had been much lighter in weight, I'd have noticed. I can't see any cracks or pinholes when I candle, and the chick is moving around - so it's alive, so far. It's just so strange.Pulled out my notes from last year. Sexing hatch, the Largest % loss I had that hatched was 13.3%. Two eggs lost over 14%, made it to lockdown, and didn’t hatch.
First hatch, largest loss thst hatched was 14%. Are you sure your initial weight is accurate? Did you see a hole or crack when you candles?