First off, the fluctuation is too high, IMO. If you can find a consistent temp that would be much better. I like to keep mine right at 80 degrees. Mine didn't fluctuate more than 1 degree either way.
If they fluctuate too high you can lose eggs or end up with kinked/deformed babies.
Denting right off the bat would suggest not high enough humidity. Do you have a lid on the box?
How are you incubating them? Shelf? Incubator? How are you regulating temps?
Do you have any sphagnum moss? If so, you can soak some, wring it out so it's not too wet and put it over the eggs to hold humidity.
One of my friends who has experimented with eggs, discovered best results once he set up the bin & just left it. If you mess with it too much, you might not do as well.
He had the damp moss and such already right off the bat.
Good luck! It's so exciting to see those little noses!
