Kinda late to the party, scuse me. How's the grow going?
So what I've spotted is your lights were too close (or too strong) at that moment. At least for seedlings. The Rh% should be between 65 and 75% until they get more leaves. Then you can keep it between 40 and 65% going lower the further they develop. Your leaves looked to be beat up cos of low humidity. Either that or your Ph is of.
In seedling stage 24C to 26C would be the aim, given it's humid enough. But 21C would be the lowest you'd go. You can aim for up to 29C during late veg but I like to use 26C as the sweet spot.