If mine does this it’s most likely that he needs to do a couple of massive burps. Sometimes it’s when he’s about to fart or poo too. But every baby is different so that might not be what is going on with your baby!
Mine is doing this also I think it's just a fussy stage unfortunately as he just doesn't need anything but just wants to be a melon and not take his bottle 🤣
@Emily mine also does this when she is tired
My baby does this sometimes. The only thing I’ve seemed to work out is she does it if she is over tired! To the point I haven’t been able to feed her but after getting her to sleep for an little bit (sometimes only 20mins) she feeds lovely