If they’re hatching days apart, it probably means the temp fluctuated during incubation and/or there are hot and cool spots in your incubator.
It is very unusual for eggs set the same day to hatch days apart. So there’s probably some wildly different temps going on in there. Next time I would move the eggs around each day so they all experience the same hot and cold areas equally. You can also test the temp with a calibrated thermometer all over the incubator area and see where the temp fluctuates and try to just keep them in similar areas.
