Do you turn them? like side to side or just leave them alone?
I incubate them in a plastic egg tray for incubating so they are upright the whole time. For hatching they just stay in the egg carton no turning in lockdown.
As for putting eggs on their side for hatching, I have lost chicks to that too they pip on the side that is down and suffocate. I almost think there is a no win way to do them..... but the egg carton seems to yield more chicks..... it seems anyway.