Having looked at the "turn" settings on the incubator, i think i didn't take into account that some off the eggs were smaller and had it set wrongly, so that the LS egg turned properly, but the others turned but ended up back in the same position,
try incubating some of your own
each time i have used it i have had one of my own, and they have hatched right on the due date,
strange, i suppose its a learning curve, i'm picking things up every time