your little guy may just be a little stressed. I wouldn't mess with your temps they sound good. I would switch from aspen to the cypress or a reptibark type substrate. I then try feeding they little guy in a week at night. They are really nocturnal and he may eat better for you in the pm hours.

I have had my Priscilla now for about 2 years and I have always kept her on reptibark at room temp which in my snake room is 78 to 84 depending on the time of year. She has only missed a meal a 2 or 3 times and it was always when she was deep in the blue.

Let us know how your little guy is doing.