He could be OT from a long day or UT from a shorter A before bed, it's all part of the silliness of transition unfortunately. I would give serious thought to setting BT and if you allow a nap capping it short enough so BT doesn't move by more than 30 mins. We did 7pm BT on nap days and 6.30pm on NNDs and were pretty much on a 20 minute catnap by the time we were getting this much nap resistance x