What could be causing these sugar leaves to be twisting/curling?

Plant looks well over fed in general, which can cause big leafy growth at the expense of bud size. Curling leaves like this can be an indication of a magnesium deficiency. Personally, I would not worry, plant is fine, just over fed though.

Most probably wind damage. Try to deduce speed or make intervals, 50 min on , 10-15 min off. High temps, intense light and overfeeding is an option too, but by twist and fan proximity - i guess its wind damage.

Try to gently look under the buds in that area -- any fuzz or slime on stem? Obvioulsy none is the preferred answer. Could also be a swing in pH, if it happened while it was growing... if it occured afterward it's not changing growth rates due to ph swings. Believe Boron def and tox can cause twisted growth. This would more likely be pH related as trace elements are usually in a soil or part of a soilless fertilizer regimen, but never know. some manufacturers with marijuana branding are completely incompetent, lol.