I never heard of turning the piston around in a gas gun to shoot lighter/heavier loads... I suspect it wouldn't cycle at all with the piston reversed..

In long recoil operated guns like the Browning A-5 and Rem 11-48, you can turn the FRICTION RINGS around to adjust for lighter loads... Perhaps that is what your source was thinking about..

Your gun may just need a few hundred more rounds to "break it in"... I bought an SA grade 1100 years ago that malfunctioned a few times the first 1000 rounds or so..After that it was fine..

Another thing to check is light rust in the chamber...Brush the chamber real well and keep a light layer of lubricant in it and see if that helps..

Of course, you need to keep the piston assembly, gas ports and the outside of the magazine tube clean of powder residue..Don't go overboard oiling it..The 1100/11-87 was designed to function without much lubrication, especially on the pistons and mag tube..