Switch the lights to 24 hours on and after a couple weeks youll see new growth. Sometimes the new growth looks weird at first but after awhile it gets gowing again. Assuming that you flushed the medium of ferts pryor to harvest I would also suggest giving them a dose of some high nitrogen fert.

You should switch to 24 hours before taking the cutting because reveging and cloning are both very stressful and to do both at once is not recomended IMO. I'm not saying it can't be done but it's not too much work to reveg em and then take cuttings and your success rate with the cutting will improve greatly IMO.

Good Luck

Laterz