I'm working on a friend's 2016 Stumpjumper with a 1 month old Eagle GX drivetrain and ran into an interesting issue. In the 18t cog, the outer chain plate catches on one of 2 specific teeth on the adjacent 16t cog. These 2 teeth have the same profile (several different profiles if you look closely on these cassettes). When it does this, it clicks quite audibly. But, I can make it go away by adjusting the barrel screw on the shifter counterclockwise 3/4-full turn. However, when I do that, it causes significant lag (and occasional non-shift) when trying to drop down from the 32t to the 28t cog. There are no other significant issues with up or down shifting on the other cogs. I verified the hanger alignment and it is true. I cleaned the chain and the cassette, and relubed the chain with no improvement. See video please. The tolerances on Eagle are tight, one reason I have stuck with 11 speed. Is this a defective cassette? Or something else? I'm considering taking a file to the 2 problematic teeth and grind a bit off the inboard side. She's got a 100 mile race this Sunday and I'd like to fix it asap. Thanks alot.