I run windows 10 and an AMD RX580 Graphicscard where I have my monitors hooked up via Displayport. My stereo headphones are hooked up to my monitors 3.5mm audio jack. Everthing works fine til my computer goes into sleep. Then Windows can not see my audio device any more för the RX580, only my built in soundcard on the MB.
Only way I found so far is to reboot the system to get the audio working again.