I think they're supposed to fill out in the 5-7th week. That isn't a deficiency, it's nutrient burn - the bubba kush got it worse than the gg #4. They're very nute sensitive/possibly a little build up from twice a day feedings at 1.2 EC (I've bumped down to 1.0 now) even with dripclean in the system.
ETA: Depending on if you count the start of flower from the flip or from the first sign of flowers, it was two weeks before the first sign of flowers and if that's the case they're only on day 19.