Gotta be isolated - never seen a report like this before, about a Faxon barrel. They won't sweat you over it, either - they know their business, and will take care of you.
Good work on tracking everything down, boot.
One thing I was gonna say, prior to the latest round of testing on your part - the gas port diameter in the gas block is 0.125". If you have a perfectly good barrel, and the gas port is slightly off... slightly... you can align the gas block, with it's giant 0.125" opening, get it perfectly straight, and still fully cover that slightly off gas port in the barrel.
Not the case here, something is off with the barrel. You'll get taken care of, for sure.