5 month old spitting up hours after eating

My baby boy has always spit up lots since he was born, I started using formula at 6 days old (please don’t judge, there’s many factors that went into the decision to switch, a big one being my mental health) and he would spit up all the time, after he burped which I know is normal, but even hours after eating. At his 2 month check up I brought it up with his doctor and he confirmed that my son did have reflux based on the information I gave him (spitting up, gasping, crying during bottle, etc). He suggested using Enfamil for babies who frequently spit up. This formula does help a lot, it is meant to thicken in your babies stomach. My son is now 5 months old and I find that he is still spitting up hours after eating, it is not as much as before but it’s still happening when I don’t think it should be, the formula worked great at first but it’s becoming more frequent. The spit up is also very chunky because like i said, this formula is meant to thicken in his belly, because it has rice starch in it. This formula is also pretty expensive and costs us about $200 for a month supply.

I know it’s normal for babies to spit up but does this seems out of the ordinary? Has anyone else experienced this? Should my son be out on some type of medication?