Not working with grendel - Cryptic 6.5mm Grendel II Extractor

I have a nice Stag Arms Pursuit 15 upper in 6.5 Grendel. It's 18" barrel length with rifle length gas system. Purchased as complete upper and paired with a complete premium Diamondback lower, their "Diamond" line.

Being completely new to Grendel, when I started having issues, I thought it was the upper, maybe not enough gas. After exploring this and searching online, I started suspecting the bolt, and especially the extractor. I purchased two Trybe Defense complete BCG's with 6.5 Grendel bolts, and both of those were not functioning - failures to extract, ejection issues, double feeds, bent casing neck, etc. I also tried swapping in this Cryptic extractor - same issues. I've tried buffer weights from H3 all the way down to stock carbine buffer 3 oz.

After learning that Grendel extractors need to have a certain geometry, especially to avoid having "claws" or "fangs" that grab onto the rim and prevent smooth ejection, I ordered two complete bolts from Grendel Hunter. Ran 40 rounds of the same ammo flawlessly, with different magazines. The Trybe carrier works just fine, it was only the bolt and extractor.

Trybe Defense BCG's seem to run fine in 556 and 308. But calibers like Grendel require someone with attention to detail to manufacture them.

Comparing closely this Cryptic extractor to the one I got from Grendel Hunter, it's not just the way the corners are rounded, it's also the width of the groove where the rim of the casing fits. I am well past returns on this one, so I might try dremeling it to see if I can get it working.