Hun I really think it's a change in his sleep needs and part of the 2yr developmental leap. My DS was exactly the same at this age. I'm not sure there is anything you can do other than offer him opportunities to sleep, and ride it out. For me, all the tweaking and guessing what time he needed to nap, or what time BT needed to be was driving me crazy, so I just stuck with set nap and set BT and whatever happened, happened. I think he gives you better naps at 1pm so what about setting nap time at 1pm and BT at 7pm? If it takes him and hour to fall asleep, so be it.