Thats one interesting plant! What strain is it?
Hard to tell from pics, but could be burn, could be a deficiency. Nitrogen deficiency is ok at this point, yellow leaves that fall off is the norm.
Yours are very green for so late, are you still feeding them nitrogen? What are you feeding them?
Id just hit them with water at this point, im a less is more person. See what happens from there. Good luck!
PS- beautiful view from your balcony!