what causes the female to stop producing flower?

Ok I noticed about 6 weeks into the flowering, that it stopped flowering but still continuing to get larger and trichomes are produced greatly but bracts production halted and the ones that grew, are continuing to get big. Don’t they usually get bigger and multiply? Seems like mine stop multiplying but continuing to grow bigger for the ones that did developed. Making it look like pop corn nuggets.
This pic above is a clone of the first pic.

When did you defoliate?

It may seem like it's not, but that plant is still stacking for sure.

They'll get bigger.

You'll be surprised at what they'll look like in just 2 more weeks. Your approaching mid bloom. There's quite a bit more to come.
You did an excellent job at opening up the canopy. Whatever your yield may be, it's going to be sticky!

Cannabis doesnt stop flowering until the plant dies or switches back into veg due to the light cycle. There are different phases of flowering...initial transition stretch, flower set, bulking, ripening, etc.

Those buds look a little delayed for week 6 though...looks more like week 4

I personally think it stops stacking when the plant sinesces(?) or "fades" but i could be wrong.