If they are still moving about then there is hope. It voids my hunch of what might have caused it. Basically the temperature was a bit low and they are delayed in hatching. Which is fine. My hunch which if still moving wasn't correct was if humidity is really high for first 18 days the air cell doesn't develop enough and if extremely high will fill with some water so the chicks when internally piping either have no place to put beak and breath or there is enough water in there they aspirate and drown anyway. It's actually quite common for first time hatching attempts as a lot of literature state extremely high humidity which isn't right at all. Only for last three days of incubation should you be high.