The solid advice on humidity matches my experiences as well.
I've had the same issue with most every ISOM, one time or another, as you're having with the Cohiba's. I had a cab of PLPC's I thought I was going to have to chuck...they were all "plugged" and no fun to smoke.
On the advice of a member here, I've been running my coolers at around 65%, and my smoking desktop 60-62%. The difference is like night and day. All smokes, ISOM and non-ISOM smoke far, far better (for me and my tastes, anyway) and plugged or hard to draw smokes are almost a thing of the past.
At least one guy on these boards I've talked to runs his cabinet between 58% and 60%. I think there's something to that....
Regards - B.B.S.