How peculiar that they're not laying yet. The light will affect this, but usually young birds like that will lay anyway.
Are your other birds laying? How much?
It's a long shot, but you might want to check the water that comes out of your hose for chemicals. An ordinary home water test will do the trick--make sure it tests for chemicals, not just pH and bacteria, etc. Last year, I discovered my hose was leaching chemicals into the water that had suppressed laying for ALL of my birds (ducks, chickens, AND quail).
Installed a carbon filter, and they started laying again a few months later.
Another possibility is that you have an egg thief--maybe a small snake is stealing the eggs? Can any other small animals get in there--maybe a rat?
Good luck figuring it out. How frustrating!