Try to change the milk powder. Maybe because of the taste also. My son was on that very brand too and he hated it. He kept pushing away the milk until I changed it to a different brand
I did mix feeding but more on formula, I did change his milk last time as he got bad reflux although this Nan his reflux and spit up ok I did change the teat but he stilldrink half
is he on Formula from the start or? have you tried changing the teats?
W.