Could be going through a shed too. They can get cranky. Have you tried BSFL/nutrigrubs/phoenixworms/calciworms (all the same thing)? If he likes the wax worms he will probably love those, and they are much more nutritious. They don't need to be dusted and can be a staple feeder, although a little small to be the only staple feeder. You can sprinkle some on top of his salads as a lure. Silkworms are another great staple if you can find them. I'm guessing you are in Canada so no dubia roaches, but I believe there are a couple of other options like Surinam or Australian roaches if you wanted to try something different. If it is brumation, I'm not really sure about how to prevent it, someone else on here might be more knowledgeable about that. The other potential issue that occurs to me would be parasites. It could also just be that he doesn't need as much food anymore because he isn't growing as quickly. Freaked me out the first time my guy refused his bugs too, but I've pretty much learned to follow his lead. As long as I'm offering and there aren't any other signs that something is wrong, I trust that he will eat what he feels like he needs. Hope this all helps!