Lisa ,
Chances are that your plated is wild caught and it might just be a natural brumation period with the change of season. Also sometimes lizards get bored with getting the same food all the time. Try not giving food for a few days then try something different like cooked ground turkey or earthworms. As long as your plated isn't losing weight it's probaly nothing to worry about but if he starts to lose weight take him to a herp vet. Good luck