8 months old and not able to eat foods

My son is still not able to eat with a spoon he still pushes his tongue forward every time I try feeding him. The other night I tried mashed potatoes and he gagged then got sick. I didn’t say anything at his 6 month appointment because I thought he would outgrow it and maybe it was just the food but it’s with everything and nothing has improved. My daughter is almost 20 months and she never had this problem.

Anyone ever have this problem? Thank you

Edit: I should add that he can’t eat food at all he won’t feed himself and even if u use a finger to give him food he struggles eating and anything he gets down he will get sick after.