"While none of the parties involved are able to confirm this, a statement from GE that it has introduced an “improved coating process to the mid-shaft of new-production GEnx engines” would appear to define this as the most likely cause."
Near new, and yet to be mounted engines are in failure? Not Stress, or fatique?
lomapaseo, can you provide several examples of this in the literature?
Since threads are not ordinarily "coated" but need to efface each other clean,
the fix appears to be impossible as described. Perhaps the nut and threads are encapsulated with an applied coating. Not familiar.