Your LGS are 15 series,yes? If so, then the higher resistance compared tomine would make sense.
glad your electrodes are fine. I've sent an email to Brisk questioning them about the condition of my 6. My friend that ordered plugs over the phone from Brisk, informed me of his conversation with them. Sounds like they are not the brightest people. The first email reply I received about the center electrodes kind of confirms his experience.