Well first it's a male so it's not that surprising however before telling to scent I would rather know what their setup is in details because the issue could lay there same for feeding how it's been done, how much when the animal use to eat.
Scenting is a step backward that I do not recommend unless everything else failed. Additionally I would start with common scent Tuna, Vienna Sausage, Chicken, Salmon, Anchovies, Hard Boiled Eggs and Toad as the very last thing.
I get really great success with hard boiled eggs including them eating it
Considering the size it's not something I would be overly worried about either but I would definitely investigate to see if there is a way to get him back on track.