Weird thing about the 420 crop.... no two plants seem to be the same. Of the 2 Blackberries, one is showlng LOTS of purple and the other shows none, although both are the healhiest of the batch of 420's. The Sour Diesel's have stabilized but the bigger one started out with lots of leaf deformation. The Gelato is in a world of its own with corrugated leaves. I had a CBD version of a 420 plant that showed that same phenomenon last year. No clue then either. Bugs don't seem to be present on micro inspection.
My gelato has the same problem since seedling aswell, just some slight discolored green, but hasn't seemed to affect the grow time, all 3 of my fastbuds started flowering at 21 days