My boy has been doing this alot recently, he is showing signs of teething so we use the teething granules. We have also started just offering him the bottle as much as we can throughout the day to get food in. Or sometimes give him his dummy and then swap it for the bottle! This behaviour has coincided with the sleep regression, so maybe it's all linked?
I read that it’s normal for babies around this age to start wanting the milk in “two courses” if you like, so with roughly 15-20 mins break between. My girl was doing the same and since leaving a gap she finishes the second half no problem xx
I’d ask ur health visitor first but my daughter is the exact same and we started weaning her and it’s started to make her drink more when she has her bottle x