Baby spit up, Help!! 😭

My baby is spitting up all the time, we switched bottles to the avent ones, and are also the tommee tippee bottle, he was going so well, not even a dribble and then the past few days he's been spitting up, we are giving him and his brother more formula, they were on 90ml but were always hungry after so we went up to 120ml, his brother tolerates it fine but my my other one keeps spitting up, he spat up not long ago and it was a fair bit, was not forceful and it came up with a burp. I've tried everything from burping frequently and keep him upright. Idk what to do anymore, any ideas??