I am feeding Lily the Royal Canin puppy until I can change her to home cooking. I will change her at one year old. My other two love the home cooking and do well on it. So I plan to change Lily over as well. That way I can control what they are being fed.
The only other food I use is Science Diet I/D when my Rosie is sick. She has a bad tummy. Lol.
I think I would leave him on it for a bit. Let him adjust to his changes then decide what you should do. Lily is my first puppy so I am no expert. Rosie had trouble with Wellness but remember she does have a sensitive tummy. We also tried BB. They would pick out the life bits. I got tired of picking them up. Haha. So I decided to home cook. You can get a recipe at petdiets.com if interested.