Need the pro`s advice...idk whats going on

Hi all, so i thought im growing Royal dwarf auto (royal seeds) but after
almost 3 month im not seeing any sign of flowers. growing in Coco + perelite,
Dual specturm light 250w, Ppm around 1800, using Sensi Bloom A+B.
3 days ago i switcthed the light to 12/12 with the thought its not an auto after all,
i mean i got the seeds from a friend that told me its Royal dwarf so i can`t
be 100% sure about it. still nothing changed, i really need you advice here cuz
i have another grow in the same closet thats growing great but got no space
cuz of the Royal dwarf (i split the closet to veg&flower). i learned my lesson with
unknow seeds =/ but i really want it to go good this time.

really appeciate your help here =]
thanks!

give them a week or three in 12/12 wont happen over night

Ya it'll take longer than just a few days to notice flowering I just switched my unknown seed to 12/12 on Monday but I've read on this site it could take up to 2 weeks or so to notice flowering/sex. Good luck I hope u see some flowering soon!

mine are on day 12 of flowering, 2 of them started showing signs of being female after a week but the other didn't start showing till today. Each strain has it's own characteristics when it comes to flowering so it could be tomorrow, might be 2 or more weeks before.