I'm starting to have some browning and leaf discolorations on my ficus cuttings. They are about 2 months old...started out 4 inches long with 2 sets of leaves. As you can see in the pictures I have had some great growth in that time. This last week I have noticed the problems on the leaves you can see in the pictures. It has happened to all of my cuttings. I have never had an issue with the ficus these cuttings came from.

Growing conditions are under grow lights, temps between 75 and 80 degrees. Humidity maintained around 60 %. The soil is the same I use for everything including the ficus these cuttings came from...Baccto Elite hp high porosity 35/65, screened 1/4 pine bark, screened 1/4 pumice, and a little greensand. I water when the soil is fairly dry but I make sure it's not completely dry. The soil in the pictures looks really wet but that's because I just watered them.

I treat the cuttings and the ficus they came from the exact same way. The only difference is the grow lights. The parent ficus has never been under lights while the cuttings have always been. Could that be the issue? It seems odd that they grew so well under the lights until this last week. I'm stumped...