Infant puking milk

My LO is going 4 weeks in a few days. We are BF him in the day and FM at night. He’s currently drinking 90ML (LO weighs 4KG) for both types of milk. He often vomits out milk after maybe 30 mins to an hour of drinking the milk despite already burping him. Are we feeding him too much milk? He occasionally pukes out BM but for FM, it’s getting more frequent. Almost every feed. Please advise 🙏 FTM here.