I know nothing of your enclosure but with humidity issues I recommend placing damp moss in your hides. This gives me perfect sheds in a tank with low humidity.
Having the moist moss in the hides make the hides more humid than the rest of the tank. Since the snake spends most of its time in the hide it directly benefits from it. During a shed I keep it moist and during a non shed time I make it moist and then allow it to dry before adding moisture. At the start of a shed I soak the moss in water and put it in very wet. Moss is cheap and its easy to maintain.