Look at your temps and you might have the answer.
95F is too hot. 75F is too cold. I assume you are checking ground temps with an IR temp gun and your heating elements are thermostat controlled.
The hot spot should be no higher than 90F (88-90F range is ideal) and the cool side 78-80F, with a temp gradient so the middle is about 82-84F.
Depending on where you moist hide/humidity chamber is, he is probably just trying to get to a comfortable temperature.
He may also, as KMG said, like it in the humidity chamber because it's secure and feels safer than your other hides.
You should have identical hides on the hot and cool side that feel snug to your BP. However, fix your temps first.