Yeah airflow sounds like a possibility , there is ZERO circulation in the room ( but plenty of air exchange. )I have the same thing going on with all of my clones right now. But way worse. All new growths are doing this weird curling , mutation. I have been reading and its seams to be either lacking a fert, too much fert, overwater, or not enough airflow from what I can grasp. Thats where I'm stuck right now.
Really ? I never heard of that before !Looks like a Magnesium deficiency to me. When the edges are curling up like that it's a clear indicator. Try adding 1/2 - 1 TBSP per gallon of epsom salts to water. This should correct the problem. Dissolving the salts in warm water is the easiest way.
You can also try Cal-mag if you like. Your local hydro shop should carry it.
Good Luck!