Sarah I really don't think you are doing anything wrong - he is probably just a cuddly baby - and I wouldn't get too hung up on "milestones" at this age for a start (hugs to you). Flynn was always out of whack on his charts and milestones - better in some things but slower on others, but like most kids he has turned out fine so far. And rolling at 4 months seems ok to me? but I have forgotten most of these milestone markers and probably won't bother with them with this upcoming bub.

As for the floor play on his own, how about putting Noah on the floor and sitting next to him while he lies there? Often bubs want you near them. Maybe lie next to him, then gradually move further away over a period of days.

Are you putting him under one of those dangly toy things? Flynn hated stuff "in his face" - maybe Noah is the same?

HTH....