Honestly, the exact opposite happens to me when I start dropping temps, but I'm not doing it till Nov. Once those winter temps start kicking in, they become ravenous. Did you make the changes gradually? Maybe that has something to do with it, as I change things by 1F per 1-2 days till it's at target winter temps over the course of 2 weeks or so. Are these all virgins? If they are then the time of years doesn't matter as much so long as you bring them back up just as early in the year.