4 months old feeding less

[FLA87]

Our (almost) 4 year old seems to be feeding less and is a bit uninterested in his bottles.
He's always been a big boy and was on 4oz bottles 6 times a day from birth. We had reflux and wind issues but he seems to have grown out of it all now.
By this stage I would expect him to be taking 7oz bottles (has dropped his 4am feed so only getting 5 bottles a day), and he did go up to this for a while, draining all bottles, but has dropped down again.
His biggest bottle is his midnight one, he will take 7/8 Oz .
For his morning bottle I would expect him to be starving but he will take a max of 4 Oz, today was only 2oz.
Midday is always the worst, couple of ounces, seems like he couldn't care less. Cries like he is hungry, will fussily (wriggling, spitting out) take a couple of ounces then just wants his dummy.
4pm and 8pm vary, usually takes between 5 and 7oz.
So when you add it all up it doesn't seem like he's getting enough to me but he also doesn't seem bothered by it. He's a very happy, active, chatty (babbling) baby and if I wasn't counting ounces it wouldn't even cross my mind he wasn't getting enough.
At his last check they noted he was still gaining weight but had dropped a centile so he should be taking more milk, but I just can't get it in to him.
Has anyone any suggestions, been through this, or just think I'm overthinking?
Thanks

Have the exact same issue here with my 4 month old. I ve done some reading and LLL suggests that babies at 4 months get super distracted. Just now I gave her a 120ml bottle and she just had 40ml and I am as worried as you were. Did your little one get off that phase eventually?

thanks

Oh wow I totally forgot I had posted this.
From what I can remember he more or less stayed the same, and I actually had to introduce solids (some porridge at lunch made up with a bottle) to try and get more milk into him. He was way more interested in food.
He pretty quickly went on to 3 meals a day plus two bottles (one in morning and one at bed).
Morning bottle dropped about 10 months and we dropped the bed time one about a month ago, just before 11 months, though tbh he was barely drinking it, maybe an Oz or two.
Now at almost a year he just has his 3 meals plus snacks a day. He's a big boy, and is still thriving even without the milk.
At his 9 month check up, when I said he was only having two bottles the health visitor said she needed to check as he should be on more, but that he seemed more than healthy.
It wasn't how I planned it, and definitely wasn't how it was with my first but it's just what he wanted, and he's thriving now, eats everything and is a very happy content baby.

Sorry that should have said I introduced the porridge at around 5 months, not as early as 4 months