He might be about to or starting to have a growth spurt too and might actually be hungrier than usual, and waiting for your supply to catch up?

I had a really similar thing with DD, (although it turned out she wasn't feeding off me properly) but at one week old the same deal...just couldn't settle her at all. It was taking 4 hours to get her down for the night! The LC did mention that this is about the time their appetite increases a little.
We figured out she wasn't getting enough as she had lost weight. (not saying this is the case with you guys, but thought I would throw it in!) As soon as I started expressing for her, she became a dream baby and was so easy to settle again because her tummy was finally full!
We are now back to solely breastfeeding as my supply has increased and we have overcome our bf probs (she had a tongue tie).

Have you tried expressing and giving some in a bottle as a top up just to see if this makes a difference? Even at night before bub goes down.

I hope this helps!!