I think it has to do with the type of paper you're using. If it's newspaper (with or without print), or something similar, it has no texture so any moisture tends to make it flat & sticking together- just as tissue paper does, only that's thinner. IF that's what you're using, & if there are layers, try adding some texture between the layers- a little aspen, or Carefresh* maybe? (*if it's available where you are- it's hygroscopic. https://www.chewy.com/carefresh-smal...ding/dp/122289 )
I use paper towels (Bounty brand specifically) to line my tanks, with a thick layer of paper shreds (mixed with Carefresh in some cases), & Bounty has both texture & strength due to what is added to the "paper"- that increases absorbency but also adds some breathability. I don't care for & never use "newspaper" to line my tanks because of how the paper itself "behaves" with moisture, & also because snakes need traction- newspaper is slippery. Your best bet is if you can find some paper with better texture, or as I said, add something between layers.
I can see why you'd worry about the snake laying on damp substrate all the time in a cool hide.