What instar is your Tityus serrulatus? I'll throw you a 5th instar Nebo hierichonticus for a 5i or above T.serrulatus. We can continue discussing by pm and leave this thread for more educational purposes..

You're starting to sound like a perfect candidate for a book. Lemony Snicket could write a sequel based on your story.

The Desert Hairy Scorpion (Hadrurus arizonensis) are found in partially arid regions, not in superdry deserts. And the beauty about this species is its capability of constructing massive tunnels by scorpions' scale often in burrows up to 8 feet deep in the wild. They do not adjust well to the ambient humidity in the air, but have devised a rather ingenious method of coping with the harsh environment. This species is known to follow the moisture line in the soil where they burrow; going deeper underground where the humidity is greater when the external environment is unforgivingly dry(especially during summer) or too cold (during winter), and coming topside when humidity is too much down under.

It can be hypothesized that Hadrurus arizonensis lives in an extremely narrow humidity bandwidth level. Too much humidity is just as bad as too little humidity. This species specific requirement is particularly apparent in younglings and where moulting takes place. Common sense says that a scorpion is in its most vulnerable state during moulting. Tweaking humidity to such narrow limits is not as easy as it sounds and Hadrurus arizonensis humbles and puts to shame many advanced keepers.

Katha Upanishad once said this - "Abiding in the midst of ignorance, thinking themselves wise and learned, fools go aimlessly hither and thither, like blind led by the blind."

I don't know why your scorpions die. Death is an act of God. Best person to ask is the man Himself.