How old is the child? It could be developmental. My 3 year old goes through periods of this, and is worse when she’s tired. Alternatively, has the child got a history of throat infections or tonsillitis? A friend’s child had chronic tonsillitis and disliked eating, associating it with pain. Once the tonsils were removed and she healed, her eating improved.

I’m guessing it’s just a phase. A very time consuming frustrating phase. Hopefully it passes quickly

How old are they? There could be a serious issue, that needs GP advice, to do with swallowing etc. and it might even affect speech development; Or it could be less important and the child is just not hungry, or perhaps is learning to enjoy the attention from going so slow, or perhaps is simply enjoying and chewing their food (not a bad thing!). Guess it depends on what else is going on!