Male corn snakes are notorious for going off feed during breeding season, however your snake being only 6 months old, this would not apply.
Corn snakes sometimes will not eat if temps are incorrect, however you state that they are.
The only other thing I would offer is, 1. Illness, or 2. About to shed.
As a matter of information - My snake once went about 5 weeks without food. He was fine, but I had no idea what was going on at the time. Then he shed, and went right back to eating.
People sometimes think the "Shedding Process" is over in a few days, and sometimes it is. On the other hand, it can also take several weeks.
If your snake appears to be healthy otherwise, and is not losing weight, I would not worry too much.
If you're concerned, a trip to the vet might be in order.