Why are my plants flowering?

I have a bunch of Venom OG's outdoors in 200gal pots. They get plenty of sunlight, well over 12 hours. Yet, the started spitting out hairs about one week ago and I can't figure out why. It's the only strain doing it and prior to flowering they were showing deformed newer growth... then the hairs. Now they're giving me 3 finger leaves. The color is nice and they're happy when the sun comes up each morning but... flowering.... near summer solstice. So weird.
I'm in Northern California where we just came out of a pretty brutal heat wave. The garden had to cope with approx 100 degree temps a few days in a row but weather like this is nothing new to me and I've never seen it throw a plant into flower. Also, the three other strains are fine. It's just the Venom.
I've hit a few of them with Nitrogen to no avail. I'm reluctant to continue this because the soil blend that they're in is pretty nutrient dense. They really shouldn't be hungry for Nitrogen. I'm currently brewing a giant batch of Compost Tea that I'll apply tomorrow but I'm not super optimistic that it's going to solve this particular problem.
Any thoughts?!?

How long have they been outdoors? Probably I weird reveg still in process. They recover from a reveg slower and weirder if rootbound as well but I doubt this could be a problem in 200s.

They’ve been outside for 5 weeks or so. They’re not rootbound. I wish that were it.

14 hrs flower initiation

14 hrs flower initiation

I ran a daylength flowerig test years ago british day length streetlight timer test northern lights they initiated flowering at 14 hrs not 12.A