Seedling droopy for two days after move to mh. Can it be heat stress?

I think it's water.. thats the only time when I have issues with water.. early on like that.. jis give it a while an let it dry good... and another thing... u got this tent and what looks to be good soil.. why don't u spend another 10 dollars and get u sum grow bags? Let them breath alot better then them pots or carton for sure.

Hello! 1. For this guy, the new light is too strong, or he was in the brightest spot in the room. The new growth is suffering due to the high light intensity! 👆 Move him under less intense lighting for a week, let him grow another 2 sets of leaves, and he will be ready for such bright light! 2. Check your drainage, make a dozen small holes about 2-3 millimeters in diameter, give the roots a chance to get fresh oxygen throughout their area and allow the substrate to dry relatively evenly! Good luck, friend! ✊😇

do you have holes in that carton for drainage? if not it's probably from the plant not being able to drain properly. That's the only thing i can see differently from this vs your other plants. Hope this helps friend. Happy growing. 👊