I have had loads of issues with realtek drivers and windows 10, maybe i can help with some issues. But have a new one my self.
firstly hardware - z906 speakers, asus black rampage 4 and optical connection.
I started having issues in september, so much so i made dual boot for win 8.1. I noticed as others had said, left speaker being dominant and just sounded off in windows 10.
the only way i got that working was to stop widows downloading drivers in the backround. you can do this in system properties. unistalling realtek and deleting. then installing mobo drivers for sound, but get this. 50% of the time i still got the issue, had to rince and repeat but it worked, a joke i know but result in the end.
so recently i upgraded to creaters addition of winows. Having done so, DTS is no longer selectable throughout realtek or sound proerties. i mean its there but if i click it , i get format not supported. on the other tab you can test DTS and it works fine in test.
So ideally what the system/realtek wants you to do is confirm you have 5.1 before it will activate. So in game options, there now isnt a option for dolby as you havent selected DTS prior in windows.
So i been scrating my head, done some DTS tests in firefox, but that didnt decode. but having done so, i seen edge is dolby compatable. did the same test in edge
https://www.dolby.com/us/en/technologies/dolby-digital-plus.html and low and behold it decodes in DTS full dolby.
So DOLBY is working fine, just not selectable in windows for default and therefore effecting steam games and the like. i put money on that DTS works fine in UWP or what ever there gaming platform is.
with the issue before i was able to work around it with patience, but without an option to select default we is fudged i believe for now. anyone gets this working for steam games and the like pls msg me