Is not normal. Usually 10min max Either he’s full, don’t want to drink Or the teat is too slow, hence he’s very tired of sucking & don’t wanna suck. Try up the teat size
No need to follow the teat size so strictly, if your baby is good at drinking the milk, may suggest you change the teat to a faster flow (e.g with 2 holes) - FYI
1h does seem long. Is it always 1 h or baby is not hungry and therefore not really drinking
can try to upsize the teat.