On two different incubators, I would hope...
What brands are you working with? Are you using additional probes to check the incubator temp against?
If it is a large incubator, it will have hot/cold spots. With my current hatch, I have had to gradually lower the temp setting on the Bator to keep the central temp low (I think it's currently at 36.5-35.5 and occasionally peaking 38.1 in the middle - the larger the babies grow, the more heat they produce, so depending on the placement of the incubator's probe, (mine is front edge) it may have started off as a hot spot, but actually be a cold spots by end of the hatch.
I've been home and checking in on mine every few hours, candling every other day, rotating egg location in the incubator, have a probe giving me an hourly graph of temp humidity variations for the last 24 hours, and offline probes in the far corner and centre of the incubator. - for a 32 egg Bator.
As of today, day 16, early quitters are out and we have 12 thriving babies going into lockdown on Monday.
Another question is what's the history on these babies? Are they shipped? Have they been washed? If they're yours, how's your flock genetics? Is everyone on high quality feed? Are your breeder's old or related? Early fails can be handling, temperature shocks, or bad genetics - later fails around day 19 etc, would generally be genetics unless you excessively cooked or chilled your eggs.
You should break them open to inspect their development level, amount of unabsorbed yolk, and to check for malpositions or water loss issues with membranes.
