If he gags/chokes/vomits at all when trying to eat chunks of food, you may want to ask your pediatrician about getting a swallowing or feeding evaluation done to make sure he is actually chewing food and not mashing it against the roof of his mouth. My son was the same way with food at that age, and we thought he was chewing fine when he really wasn't.
Most of all, listen to your gut. I felt there was something wrong with how my son was eating, but I let family members and even his pediatrician and ENT convince me that his feeding problems were due to his age or the fact that he had a cleft palate and that things would clear up once his surgery was done. Ultimately, he wasn't chewing his food and because we kept trying to give him food he couldn't eat he now has sensory issues and is afraid to try new things. We had to do speech therapy for nearly 9 months just to get him to the point where he is physically able to chew appropriately for someone his age and we just started occupational therapy this month to work on getting him to eat different foods and textures.
In all likelihood, your son is just being picky/stubborn and things will turn around once he decides he's ready to cooperate...but wouldn't it be nice to know for sure? Best of luck with everything. If you have any questions about feeding evals or anything related to this, please send me a message.
R.