If you haven’t already, join the Breastfeeding Mums Support Group on Facebook and look up the term bottle refusal in the comments. There’s soooooo many posts about it on there and advice from lactation consultants and feeding counsellors well https://m.facebook.com/groups/226228484073252/?ref=sharehttps://m.facebook.com/groups/226228484073252/?ref%3Dshare&exp=8ce3&mibextid=S66gvF
Maybe the flow rate is too slow with the bottle. My little one stopped taking the bottle so I got the next year size up, and he went for that.