I'm somewhat having the same issue, Although I believe in my case that it's due to the lamps I have for heating and living in a dryer state. After bad luck with getting a UTH to work, I switched to just using two CHE lamps which I know dries out the enclosure quicker. Right now I'm misting the cage several times a day, letting the substrate dry out in between which only takes a few hours, and I've been wetting down a pillowcase to place over the top of the screen. Which has been keeping the humidity in, and also helping with heat; So maybe you could try doing that? I may invest in a misting system that I can turn on and off myself.