if he was fine on the larger amount go back to that...
you just figured out a puzzle for me though, a new baby started in my daycare and all the mom says he eats is 3 to 4 oz and I am having to make more then that each time after he finishes that up. The last few babies have had parents like this too, wonder if the "new" thing is to tell parents a per feeding amount instead of a daily total?
If your baby gets 32 oz a day in 8 feedings or 32 oz a day in 4 feedings does it really matter? NO. ((I do not know the exact amount for that age that is recommended, just picked a number out of the air that seemed reasonable))
Go back to what was working. The MAIN KEY part of parenting - if it ain't broke, don't fix it.