I'm running SLR gas blocks on a couple rifles. One is a 16.5" rifle length gas barrel with JP SCS and lightweight BCG, and I have the gas block open just a couple clicks. It runs everything including PMC 55g.
I would recommend removing the gas block, inspecting it for anything unusual, and reinstall being very careful to align properly with gas port.I
I agree with Steve133, SLR gas some of the best customer service in the business.