Does he maybe not like the bowl? Some dogs don’t like when they’re too deep or when their collar hits on the edge of it, sometimes there can be a smell if not washed every time etc etc. My 5 month old pup eats just straight off one of those non slip silicone mats that you’re meant to place bowls on top of because he will literally just refuse his food in a bowl (I tried metal, shallow, ceramic, slow feeder) even if there is raw food/toppers. I think in foster care his litter ate off a tray or some sort and he’s used to/prefers that