I agree that eating every 5-7 days is a bit often for a juvenile MBK. I’d probably move to a 7-10 or 7-14 day feeding cycle. When I did keep them, my kings would go off food for 3-4 months every year during the winter and breeding season. You can just wait them out and they’ll eat again when they’re ready. I would sometimes get impatient and offer a small live feeder and that usually stimulated their appetites. Kings are usually pretty voracious eaters. I loved how hard they would hit their food for such small snakes. I’m sure your guy will fire up again soon.