Please quit eating the cats food despite having a full bowl!!!

I’m about to loose it. I expect the bites behavior since he is just a puppy. I expect him to be hyper. But one thing I’m genuinely concerned over and feel like crying because NOTHING seems to work is him eating the cats food all the time despite his bowl being full. We give him exactly what he was eating before and what our vet recommended and he doesn’t listen. I’ve done everything to get him to stop. We can’t keep track of how much the cat is eating because he constantly eats her food. And when we ignore him if he’s being too bitey or acting up (I’ve seen multiple dog trainers say to do this) he’s chill for a few mins until he decides to get my attn one way or another and that’s by going over and inhaling the cats food. We give him so much attention, so much love, so many pets, I genuinely do not understand it. Yes he is an inside dog but I’m also very active and play with him/walk him constantly.