have you recently changed lighting? Is that what you said above?
When going from CFL to HID, the plant was used to the CFL and it could be high temps and illumination burn.
These would make any newer grower overwater to try and help the ladies.
I hope this is the case. Especially it is easier to ride out. Move the Light farthest away and wait. (2nd illuminations post)
Are there hot spots inside your grow area? Have you exhaust in addition to the 6-8" clip on fan?
How is your Intake? I am pumping out about 300-400CFM. $100.00 Keeps me Coool and plants sway with the wind, ever so slightly. Making them stronger.
Ph could be the problem What water and soil are you using?
As for transplanting, normally soaking the plant hours before the operation and transplanting into moist soil normally is plenty.
Once transplanted normally wait before heavy watering for signs of transplant stress. If we over we add over water stress.
Can you lower the temps outside the area in which you are growing? If your temps are 85+, this might help cool them down.
Not going to touch on a solution for Ph, as if it is your problem, (still not sure with all that may have happened to your ladies) it may be more difficult to correct and could cause further damage.
If you were taking notes....
Wait, don't water till you see them droopy, move light, lower temps, NO Nutes! Keep it Simple!
How much is a cheapo PH tester?
When I saw some twisting leaves, within hours I figured it was PH, I changed my water stopped over watering, Let dry out, plant recovered.