Ok there must be a reason
So far you’ve ruled out the lights the genetics and the lights & the environment.
One step at a time I guess.
So can you tell us what you feed them and give us a basic rundown of your growing method including if you ph or not.
I know two years of this must be driving you up the wall.
Tell me something just as a afterthought have you ever had a virus
I still think it's the genetics.
Exactly what strains are we talking about?
Also, you can get a virus/viroid from infected seeds.
If you don't keep your tools clean, the badness can spread very quickly.
This includes your fingernails if you like to pinch leaves. (I spray my fingers with a little rubbing alcohol between plants.)
Do you have any pics of hermie plants? I would like to assess their overall health.
If you're doing everything even remotely right. Crap genetics is the only answer. Lots of herms in today's seed business. Especially fems from the mega closet breeders out there. Using questionable genetics to begin with. Me usually, I like to stress my plants a little from seed. Weed out the undesirables. Herm rates imho have been climbing last 15 years or so.
Agreed.
Some strains are simply more prone to hermaphrodism -- like GG4.
If a hybrid is made with 2 strains that both have GG4 in their lineage, the odds of hermie expression increases a LOT.