Just a thought, could it be that he is too distracted in the day to eat and so gets his calories in the night when it is calm & quiet & he can focus? Tracy does talk about that, and for us, this month we have had to nurse in a very dimly lit room. If I nurse anywhere else, she keeps pulling off to look around & fussing if I keep offering. I just offer multiple times during the day, so make sure she gets most of her calories then. Hope that was a little helpful