I am having a similar problem in one of my humidors. What the problem appears to be is that the beads have a limited capacity to move water. Small changes in a limited amount of air space are fine, but a big rh move or a lot of cubic area pose a problem for the beads. A sponge, or some new cigars (which are usually pretty wet) move the humidity in, and the beads trim up the humidity. Rely on them for that, but if you are off by more than a little, you will need another source of humidification to get a larger amount of water into the humidor's atmosphere.
In other words, I have found the beads are better at quality than quantity. I hope this makes sense.:chk
In other words, I have found the beads are better at quality than quantity. I hope this makes sense.:chk