Just looking at your feed bowl is that a pellet feed i can see in pic if it is I would say it could be its too big for them to eat properly. @Rose Quartz
Failure to thrive is fairly common can be from several things, incubating can also be from breeding stock. Health or bad nutrition of breeding stock. So really hard to say what the culprit could have been. You might want to give them something like nutri-drench or vitamins/electrolytes to give...
By looking at your pics of them sleeping in brooder temps should be good they are not all piling on top of one another under light. It shouldn't be the pine shavings.