What media do you use to regulate RH?

If it's something like litter or beads, is it too wet?

If they can't or won't absorb anymore water (possibly releasing it), moisture might be building in the humidor as it will have nowhere to go.

I think is what bit me in behind when mold popped up on a couple of cigars for me. I threw my litter into the oven for a bit and back into the humidor, it dropped the RH back to 66-65% and no more excess moisture.