gREEn7o0answered grow question 3 years ago Could be one of many things.
Genetics could play a factor.
Were all plants the same strain?
Even within a strain the different phenotypes react differently to feeding and stressors. I had 5 banana bomb seeds, got 3 phenotypes, one couldn't get enough nutrients and light, one was being burnt to a crisp from the same combo. One was a sativa, which was weird. But loved the heavy feeding and lights.
Could be environmental issue (temperature, humidity, lights)
Too hot can cause airy buds, too little light, light too close, lack of air flow?
Could be a nutrient/feeding/water issue
Over watering, root rot, ph lockout, lack of pk.
Im gonna take a look at your grow log and see if anything sticks out.