Do you wash your buds before hanging? I had a bud worm on one of my large autoflowers outside. Plucked it off and then spotted some bud rot. Cut those buds off and kept an eye on the plant. Rainy and humid with no sun for a week, cut the best buds off and washed them in lemon juice and baking soda, rinsed and hung to dry.
I usually do an H2O2 wash on my outdoor grows but has been impossible to find any at the two stores I usually buy at. I can't bring myself to smoke or use outdoor grown weed without washing it first.