Still looks like heat stress bro. Check the temps where the plant is closest to the lights, since that's where it will be hottest to the plant. If the temps are still cool enough there, you can rule it out and check for nutrient defs.
hey guys this thread is old but iv planted 7 seeds and started to grow again, got new compost and new pots. still got the same problem happening brown leaves. anyone got a clue what is happening