Forest bark? What is that? Just regular bark? Or does it have pine or cedar in it?
If the snake is not hiding, then it is stressed out. No Ball python is a good climber as they are all mostly terrestrial. Can we see some photos of your setup?
What is the UTH controlled by? If nothing you can severely burn your snake, I would recommend purchasing a thermostat. Without anything controlling a UTH, the temps can get easily reach 130F.