First things first... what hygrometer are you using? If it's the one that came with the humidor, throw it away.
If you're using a reliable hygrometer...
BTW: To answer your question; when you seasoned the humi you placed your sticks in the humi that is at 85% RH (and I'm assuming they came from a 70% to a 72% environment already) the RH is equalizing at the 80%.
...there's your answer.
Personally, I'd strongly recommend ditching the 70%+ stuff and getting a couple of 65% Bovedas or using 100% Kitty Litter. Most cigars, IMO, smoke much better closer to the mid 60's. Some smoke better in the lower 60's. I've never yet had a cigar smoke better at 70% than at 65%.
KL is your easiest solution right now. Get some of that and pour it into a nylon stocking. Put the dry KL into the humidor with all the cigars and I'm guessing it drops to 64% and stays there. If it dips below, pull it out, give it a little spritz of distilled water, and put it back in. Easy peasy.