He may have been sick when you bought him. He may have gotten sick since you've owned him. If he's keeping his head angled upward, it could be a sign of respiratory infection. (Holding his head up helps him breathe if mucus is building up inside) I really would recommend a trip to the vet...a vet who understands reptiles and has experience treating snakes.
Ball pythons can't really be compared to corn snakes. They're typically a much slower animal, with less tolerance for environmental changes or mistakes. A healthy, thriving BP will usually spend 99% of its time sound asleep, curled up in a hide where you won't see it...and typically only cruise their cages at night when everyone else is asleep.
You say your temps are "good"...but without knowing the actual readings, how they're being achieved and how they're being read....we can't really know how to help. Same with the hides...hard to help tweak without knowing the details. And with ball pythons, it's often all about the "tweaking." There's just a lot of variables with these little guys.