Ok so it was on 12/12 for 4 weeks, then you switched it to 20/6. Total 5 weeks old. Okay haha I'm stoned and need to re-read everything.
I would have left it at 12/12 if that's what it was at from the start. Going to a 20/6 photoperiod is going to stress it and it might not show sex with that photoperiod. I don't know man, with so much switching back and forth you might get a hermie
. Maybe just let it veg for a few more weeks then switch it to 12/12?