I had the same problem back in the day when I tried to hook up my turtle beach x42's to my pc, stereo worked simulated surround did not. The issue was that my computer did not have Dolby digital live (no modern pc does from my understanding, old software) which is the software at least my x42s used for simulated surround, I would assume PX24s use this software as well. I did get it to work but it involved a modded audio driver that I had to sign myself and could only use in windows test mode so I always had that watermark in the corner of my screen when at the desktop.
So to some it up if you want surround to work on the pc you will somehow need to get dolbly digital live support on your pc. This is the video I used to do it below. You...