i've seen this with a couple autos i've grown. it's either over nuting or maybe a light leak? i had a defective COB LED that glowed for 2 hours after it had no power going to it. I didn't realize for quite some time. It impacted more than a few grows with nanners in 1 area of tent, lol... all made sense later..
But, could cause that sort of growth, maybe? check for light leaks. check lamp for defects after power off. ducts, etc.. if leaves are glossy and leathery and super lush, possibly too much nutes. you'd know better with in real life with better lighting than what can be seen in that regard in the picture.
maybe, it's just genetics with some autos? i have limited experience with it, but i had two go all "dr. ginspoon" on me like that. Fairly sure the second was not over-fed. so, leaning toward the weak photons screwing with the plant in an otherwise dark environemnt -- autoflower or not, it's probably not healthy.