While I think everybody who is talkinga bout self polination/stress/etc.... is corecct. Do you have ventilation set up. IE Intake/outtake in the roome. If so Pollen is a possibility. Although I believe its an issue of plant defenses like people have said before me. IE, maybe you waited to long etc.,.... Is seed count pretty low? If its only 1 or 2 seeds a bud, I'd say you have some femenized seeds (from what I've learned today)
we know it was a closet. the guy above asked was the intake coming from outside suggestiog your plants were pollinated from outside.
Was no intake in the closet. No way pollen could have got into the closet. Seeds appeared very late into flowering.