from a grower who has seen 17-19 fan leaves. Not auto's though. I apologize if it's off topic, I just think genetics are complex and interesting.
I have a auto that has double budding sites and it's tri-foliating from top to bottom - anyhow - back to
tokaite's question - like others have stated - genetics.
View attachment 340947can have a lot of different genetic characteristics and mutations .
Have fun with that onyx OP.