Not if the spikes are temporary. If it goes up to 80% and holds steady, then your cigars may develop mold, or be too wet to smoke. If it goes to 80% and then comes back down to 70% or 65% (or whatever your target humidity level is), then it will just take some time for the humidity inside the cigars to come down as well, but once it does, they'll be fine.
Whatever level your beads are rated, the humidity should begin to go towards that level. If the humidity is higher than the level for the beads, then you want the beads to be mostly dry (so they can absorb the extra humidity). If the humidity level is lower than the beads, then you want the beads to be mostly wet (so they can release humidity).