It sounded like your baby might be getting enough to eat and he's signalling that he's full. I read in another post that you're feeding every hour and 9-12oz each time. Maybe try easing off so you are not over feeding?
Are you also feeding solids ?
I have a 10 month old and since 9 months, he's drinking 3 bottles that are 6 oz each. Usually he drinks 5oz. We also offer solids breakfast, lunch, and dinner.
He gets a bottle when he wakes , before nap #2, and before bed.
We feed every 3.5 to 4 hours.
Remember that after one year, babies rely more on solids and as they approach around 9 months, they might decrease their milk and increase their solids.
It's all so confusing and you only want the best for your baby.
If it helps, here is our rough schedule:
7am wake + bottle 8am breakfast 10-12pm nap 12:30pm lunch 3pm bottle + nap 5pm dinner 7:45 bottle and bedtime