This happened to me once with a Northern Lights Auto. The only thing I could figure was too many light leaks and got too dry too many times..

This is one reason why I stopped growing autos…seem very easy to hermie..I’m sure there are better breeders than I used…just gotta find them…I just use reg or fem seeds now, been very happy.

Did you run 18-6? I’ve noticed this being an issue for folks running 24. Smaller yields too. At this point it’s impossible to say really, without a hundred more questions. Lol. Strain, container size, auto reg or auto fem, light schedule, environmental conditions, feed/water schedule, pest issues, etc…. If EVERYTHING is dialed in I would have to say genetics.