Shadow 2 extraction issue fixed!!
With much troubleshooting to definitively come up with the solution, after isolating mags, larger buffer, small buffer, no buffer, original recoil spring, 11 lb recoil spring, extractor spring and extractor the culprit was the extractor itself. I bought an extra power spring and with my extractor, it wouldn't even chamber a round fully. With the new extractor and extra power spring it would. This was repeatable. So there you have it, less than 3000 rounds and I have a bad extractor. I'm just happy to finally figure it out decisively. Thanks to all who gave great ideas and comments.