Well, if the eggs are good then humidity is your problem. Make sure the substrate is moist but not soaking wet. When you pinch it, it should just barely clump and hold together. Also make sure your eggs are in a container with a lid inside the incubator. Poke two small air holes in the container and put a lid on it.. that will help keep the humidity high inside the egg container.
Then i'd add another container of water inside the incubator with no top to add to the humidity. Keep an eye on the eggs.. if the eggs are sweating, remove water. If the eggs are denting add more water. If the eggs are yellowish in color they are not fertile more then likely.
goodluck
brandon
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Dragons by Nature