Does he vomit a large volume? Has it been investigated? I would speak to the GP if it’s vomiting as opposed to regurgitation (I.e. spitting up milk), it should be looked into and you don’t want anything to be missed
Have you considered giving him in small amounts if you really must but I would suggest laying off for awhile especially solids , my girl doesn't do well with solids and I let her be, I give her formula but it small amounts whenever she needs. Babies just have tiny tummies and some take awhile to pick up and digest
Can’t advise you but my little does exactly the same thing, soon as he starts crawling around his usually sick a little x