Buds not flowering

I’ve never seen an auto that would veg for four months, not saying it’s not possible. But it likely will have to be flipped to 12/12 like a photo period plant. If you haven’t flushed it before than it’s quite possible you have a salt build up. I would flush them with about 10-20 gallons of water (depending on how long you want to sit there) and trim all the dead or drying material off. Then give them a couple days to bounce back and flip to 12/12 and start bloom nutrients. I hope you get it going and happy growing!