What's causing This??

Looking at the pics, it seems to have pretty obvious internal pressure issues, though nutrients can affect that, but yeah...watering/humidity/oxygenation is probably related. Still looks like mainly calcium issue, but water too.

Looks like calcium (mainly) to me. I'd throw some calcium, maybe a bit of sulphur at it. Watering might in some cases exacerbate those issues (like concentrating excess nutrients, making the imbalance more apparent).

Compare leaf temperature to air temperature. Adjust your humidity and/or temperature until you see 2-4 degrees delta. That seedling needs a VPD of .5 but the full flower plant could be pushed up to 1.5. For optimal growth they need very different environments.

Nitrogen toxicity can cause calcium and potassium lockout. it looks that way. adding more calcium to feeding can help. leaf curling down is a sign of N overload.do not feed them N anymore, only bloom nutes and calcium/magnesium supplement.that plant looks like a weak genetic

Might be a little off in a micronutrient like Cal or copper. Might also want to check for thrips.

She was fine this morning and check this afternoon and this happend

this is fot the hot temprature and low humidity maybe... or overfeed...