R.G.
D.,
Try going back to his original nap time of 11. The change might be stretching his awake/sleep limits. Also no one goes to bed right after they eat, so babies shouldn't either. Sound like you had a great routine in place before. Try switching back and see how it goes.
I agree too that at this age things in their world are changing and they want to be awake to watch/see it all.
Best of luck,
Rolinda
Wife, Mother, Friend