6 week old falling asleep taking bottle

[Lynx92]

My baby is 6 weeks old today, he has been gaining weight and health visitor is happy with his progress he normally loves his bottle and finishes them most of them time. Today he has only had 1 full bottle (this morning) and every feed since he is only taking small amount 20mls(ish) and falling asleep, he then wakes up crying and putting hands to mouth which he does when he's hungry so I give him a bottle and same thing happens just takes a small amount and back to sleep - should I be worried? He is totally fine otherwise. He is formula fed and has been taking 4-5oz per feed without issue till now. Any advice welcome x

Congratulations!
Try holding baby in a less comfortable position, such as holding their head in your palm rather than cuddling them. You could also try splitting their feed so that they have half before falling asleep and half when they wake.
I also used to take the bottle gently out then back in and baby would start suckling again. Don’t worry yourself though, babies are very good and letting you know when they need feeding, and if he is gaining weight he’s doing well. Any concerns though do ask your health visitor x

There's a growth spurt at 6 weeks. Growth spurts usually mean loads of milk for a few days and then loads of sleeping.