Hpa VFC m110a1

reaper em engine having feeding issues. set to 110psi getting 2.1J dmr limit here. shoots 10~ rounds than stops feeding when I apply pressure to the mag it will feed the whole mag is this a hop up issue? given that the replica only takes a proprietary mag I can't just try other mags I've tried maple supply heavy springs, pts epm springs using .4g BBS. any advice would be sick as I've tried everything I can think of