You may be in a too large of a pot, too soon for that size plant. Not a light issue from what Ive seen in my experience. Leaves will turn crispy brown like in a day or two, and theres no reversing it and it sucks the life out of your buds. I added a light to a corner of one of my tents and it deep fried my buds going forward on those tops. Luckily only a section of the plant, wasnt as potent afterwards. This looks like possible over watering, let that substrate dry up a bit and maybe think about cloth pots for the final up potting phase hella cheap on amazon.