reflux milk/teats

Depending on what bottles you're using, you could try a variflow/faster flow. The hole in the teat is bigger so lets thicker milk through. Our LG isn't on thickened milk but we've had to go onto mam x teats as the size 3 were too slow for her

I use aptamil anti reflux and teat size 3 tommee tippee. When using anti reflux formula you need a large teat size with a valve. Also I found that using a prep machine doesn't dissolve it all so I use boiled water and cool it down. That way it's all melted and doesn't clog the teat x

Get a bigger test as ur lo could be just sucking the air out of the bottle