maybe with an autoflower average you can correlate good/bad methods, but with photoperiods average per plant is mostly meaningless because of variable vege phase length.
Possibly genetics, possibly need stronger light based on pics.. can't be certain of either from given information.
Growth (vegetative growth = elongating stems and adding leaves) will stop once it is full-throat bloom phase --> producing flower and nothing else. whether autoflower or photoperiod after 12-12, there is a transition that takes several weeks before vege growth stops...
Autoflowers, i'd shoot for 50g or more. Some will just be little shits and nothing you can do about it. I have no intention of growing them anymore... weak yields, difficult to plan for inconsistent sizes etc etc... taste like shit.