Trouble keeping coolidor humid

Even if your beads are 100% clear (or fully saturated) you would get higher RH readings if you were in a more humid setting because the white beads wouldn't be able to absorb the excess humidity. Either it's really warm where you are keeping your cooler (68 degrees F sounds good though), your hygrometer is erroneous, or you have a serious leak somewhere and/or a combination of said variables.