Leaves curling inwards and upwards

I missed the second part of your question so here's the second part of my answer, lol. The little one is also suffering from the same environmental issues but also looks like there was a overwatering issue too. This will stunt the kids as their small root system drowns out. I suggest everything from the other answer, plus a dry out with the second girl. Let her root system get established and allow high humidity in the tent so she can take moisture from the air (from her leaves) to the roots, not the other way around. Cheers!

Howdy. I'm with hoesay on this. Looks to be a normal heat/light stress issue. I checked the your specs and everything looks pretty good👍. This issue, or 'tacoing'/'canoeing' is due to the plants inababilty to process too much light and/or heat. Your humidity at 60% is adequate but I would bump down your day time temps from 29 to 26-ish. Along with moving your light upwards an inch or two a day, you'll find the sweet spot and the symptoms will halt (I feel your lamp is too close, even though it's not an LED). Other then a couple environmental tweaks, you're good to go. She'll sort herself out when her climate suits her needs a bit better. Cheers and good luck👍. On your way to a beauty specimen.

Looks like they could be suffering from too much light. This would cause the curling. The second seedling just looks like a weird pheno.