I encountered the same exact problem about a month ago.
I contacted OPO and asked them to see what was going on but they couldn't really give me any...
My USB cable is about to snap in half right around USB side of the cable... =(
I've had mine for about two months and the sound quality is decent
But like some of the other people are saying, the build quality may not have been...
I flashed mine the old fashion way with TWRP and it worked flawlessly =)