The most important thing is that he is eating. How often are you offering food? He may not be a weekly feeder. Perhaps if you dial back the frequency of his feedings he’ll eat more consistently. If you’re offering food weekly, try biweekly. If you’re offering biweekly, try every 3-4 weeks. That’s one advantage of feeding f/t is that it’s easier to dispose of refused prey if you don’t have other critters to eat them. Snakes can go for several months without food, even young ones, so I wouldn’t worry about a few missed meals. Double check your temps, and as long as they’re in range, then let him eat on his preferred schedule. It’s also getting colder in some areas and lots of snakes will slow down or go off food completely until spring.