The guys down under did a very scientific study with some micro biologists on plume and mold. After they analyzed submitted samples of 'plume'.....they found mold in
every case. It's worth looking up and reading. I'm 95% of the way to 'there's no such thing as plume' but remain open to facts as they come out.
Your hygro readings seem very reasonable, but without knowing how the cigars were stored before you got them, there's a piece of the puzzle missing. Too many vendors sell very over-humidified smokes on purpose, claiming they're doing the customer a favor (as was told to me). Their logic is lots of customers don't have proper storage, so they ship them wet.
The other piece of that puzzle is folks generally don't realize how long it takes for a cigar to 'equilibrate' to the environment. If you take a 'wet' cigar and put it in 65% storage, while the wrapper will dry out quickly, the binder and certainly the filler will take much, much longer to get there. Months, typically. "Dry boxing" a stick for a day or two does little to nothing, other than the wrapper.
....so, hypothetically, a wet cigar, stored with other cigars (at the vendor) which may have shown mold, shipped to you, stored properly but drying out slowly....and mold can take off. A 100% guess on my part, based on my own experience.
Get them out of the box, wipe them down, wipe the storage with DI / Ag, and let it dry out with the lid open for a couple days. Once everything has calmed down, you can start over. It's happened to almost everyone at some point, usually with the good stuff. Hang in there, good luck...
