When to be concerned about solids

My almost 9 month old has little to no interest in food. He used to around 6 months but then he slowly lost more and more interest. It’s like pulling teeth getting food in his mouth. He won’t let anyone give him food with a spoon. Anything he does manage to get leads to gagging to the point of tears and vomiting, every time without fail. He puts everything else in his mouth without hesitation or issue, it’s only actual food he has a problem with. He loves drinking from a straw cup and he’s constantly shoving his fingers rather far into his mouth. His poop hasn’t even changed, his getting such little solids into him. The most successful method has been “popsicles” of purées, milk, or yogurt but even the contents will cause extensive gagging most of the time too.

I don’t know what to do aside from increasing exposure and practice but it feels so futile and frustrating to go prepare a meal that’s just going to end up on the floor or in his hair. I’ve never seen an infant gag like he has before and I’ve been around several babies during this process via family and friends. I’m bringing it up at his 9 month appointment coming up but what can I do until then? Is this even a concern?