Sputtering Regulator.. broken?

All of a sudden my regulator seems to be sputtering a bit and the needle wavering some. No hissing it seems.
Its a 10# tank, fairly new (only through 3 kegs and fermenter purging) so it shouldn't be empty - the guage still reads above the red line.
Several weeks ago I did get some beer up the line, but cleaned it out well and its been working since... Is it failing? Tank going low? Could it be a result of beer contamination so long ago?

maybe try taking it apart and cleaning it again? maybe something started growing there?

please tell me you at least put check valves on your gas line now...

got the check valve the next day.