Ok big problem...

Its now been 15 days since the germinated seedlings were planted. They've been kept at a humidity of 48% and 75 degrees Fahrenheit on average. As of now, all three white widow's have sprouted to the point where the seed cap is visible on top of the soil however, no plant material save for the seed cap is visible. The plants have been watered approx. every 8 hours with just enough water to make them damp. After 8 hours had passed, the soil would still feel damp, and I would water accordingly to make the soil consistently damp. The airflow is good (449 cfm exhaust fan). Each plant is directly under its own light, approximately 2 inches below. Two of the pure power plants that were planted into the jiffy pellets, never sprouted, and we dug them up and found no root structure at all (couldnt even find the original seeds).

Should we ditch the jiffy pots in favor of seedling starting soil?
For the plants that have a seed just protruding out from the soil (its been roughly a week since they were first visible and they haven't grown), could those possibly be transplanted?

I really need some help because we dont want to lose our plants... we only have four unstarted seeds left and really want to save the ones that have already been started too. Seed origin is definitely legitimate. Any and all suggestions are welcome and greatly appreciated. Please need help from experienced growers.