Hey, so, if you have them in such low light. Or if that's dark idk.. You need to stick to a set 18-6. It only takes a few days of a late vegging plant to do this. This isn't what's supposed to happen. Yes, a vegging pheno will show sex. But, to get like that. It takes a lot of not turning your lights on at the same time every day (you do have 24hr on/off simple adaptor right) Anyways. I suggest you actually make sure when they go into dark its fully dark..and with lights on. Make sure they aren't been shadowed. A way you can kick start them quicker back into veg & growing bigger. You need to use bigger pots. They're very small. So it's a factor of a few things stated above.. uppot to a new bigger pot. And make sure they get 18hrs of good light (that comes on at the same time on/off) everyday at the same time.

Its a normal phenomen called preflower and will show on every plant after some weeks of veg.