I’ll start by saying 86 degrees is pretty hot. But you couple that up with 1.95vpd and you’re looking at taxing roots to do all the drinking. If you want to run that temp and humidity, you need to mist them 2 times. Right after lights off and an hour before lights on.
Best bet is to lower your temps. It would help to increase humidity and get your VPD down to .8-1.0 if possible. Which means at 54 humidity you need to be at about 65 degrees to be at optimal VPD. Stepping up humidity to achieve that and remain at the 80s in temps you need 75 humidity.
They are short and stalky, so your light is adequate. But make sure it isn’t too intense of light. When she doesn’t get tall she focuses structure. Not getting tall or lanky means she senses the light is appropriate distance/intensity and stops stretching for more light.
But it is possible light is too intense. If light is too intense she will stay short and low, but if she starts making her next set of leafs, nodes will be tight and upward growth slowed as she focuses making new sets and nodes. If the light is too intense she will burn and stay stunted.
If you lower temps to 75-80 and no more, and keep humidity around 60s, they will love it.
I personally never run seedling stage with a dome. I control VPD and lighting. I have never tried to push my plants to grow faster with increased temps. It just isn’t needed and means you need higher humidity upwards of 70%+, to run high temps.
They will grow a lot more healthy if you focus VPD and don’t worry about high temps and “faster” growth. Because in your case, it is uncontrolled and the heat is stripping all moisture from the plant. Drying and crisping up. Using reserves to fuel water demand, resulting in dry crisp leaves as she cannot supply enough through the weak root structure at such a young age. These high temp veg attempts increase room for mistakes or damage to the plant. The one with issues, has a weaker root structure. But don’t rule out that the one “doing good” isnt stressing out also just able to uptake more from better root development than the other.
You need a dome to run that heat. Or increase humidity substantially. Or reduce temps.