I agree with what Meoshia and Jemma said. Royal Canin is not the greatest food and considering how much it costs, you could get a better quality food for the same price. Also, don't be put off from feeding him wet food. You often hear people say that wet food isn't as good and it seems to be mostly based on teeth health, but kibble being good/better for teeth is a myth. Wet or dry, it doesn't matter, what makes a food good or not depends on what ingredients are in it. You could find a high quality wet food on dogfoodadvisor.com if he prefers that. As the others said, it might just be that he's still getting used to his new home though. And I agree with Meoshia, we'd love to see pictures of him.