LG Flash Tool Won't Recognize Phone :( topic

I've got an LG G3 by US Cellular (US990) that I'm trying to downgrade using LG Flash Tool. The problem is that it's not being recognized by Flash Tool or by LG PC Suite for some reason. When I plug it in in normal Android it recognizes it whether it be charging, MTP or PTP. But when I go into download mode these programs do not recognize it and so I can't flash anything. Anyone had any similar problems or anything I can try? I have installed the drivers multiple times and I'm on Windows 7 64 bit. Any help or suggestions are greatly appreciated, thanks!