Too Wet… Too Dry, she drooping!

CALCIUM UPTAKE.... AND LOTS OF MAGNESIUM

Hey buddy. Well it's I can tell you it's not the environment, over/under watering. Your problem is down below. Lift up the pot and see if it feel lighter/heavier. Make sure if there is any overwaterinh that the substrate isn't blocking the drainage holes. Other than that, it's possible just a bad seed that's weak, or has root rot. With so many sisters being ok and just that 1 droopy it's the only thing that makes sense. If I were you, cause you have so many. Uppot it again or just repot with just root stim or so something that breaks down root rot like tarantula, there are many root washers, stims out there. I think a lot of ppl forget. What goes on down below is actually more important than what's going on with the top. Do some investigating down below to find out what's happening above Good luck bro.

Sometime, some phenotype just have dropy leaves

I assume something is wrong with the root. But that's how it is sometimes with the plants, 36 are healthy and one dies. Wait a few more days but I don't think she will survive.