Spitting out milk

Hi mummies! My lo is turning 1 month in a couple of days and we have since increased his formula intake from 60ml to 90ml. I noticed that my baby has a hard time burping and will sleep when he's thoroughly full,making him not want to burp and that results in spitting up the milk he drank. Is this normal or should i reduce back the formula intake to 60ml? Should i change his formula?(lo is currently on dumex dulac) Mom told me that baby might have colic and we have put on a binder for him. So far he's only spitting up milk if he doesn't burp so i don't think it's colic. Does anyone go through the same with your lo? How do you tackle the burping issue? I usually don't let him lie down till he burps but kinda tiring for me as i have chores to do and i can't complete them if i have to be with my lo all the time. Help please!