I'd definitely try another mag as well, could be that simple. I had no issues with cycling from 10.5 up to 12.0gr with my pistol. I has a non-adjustable gas block and is presently not suppressed (waiting for the Feds to give me permission to build it.. lol). I am pretty sure my oal was 2.180, don't have all the load data at hand.
and thanks Outrider, been around, just a bit quiet of late.
I thought I had it. I tried a new mag and with the 11.7gr load, it ran fine. I dropped back and tried some of the 11.2gr loads in the same mag and got a failure on the last mag.
I may have to try fiddling some more with the gas block setting.