you need to disable updates in windows first. Then uninstall your current audio driver in control panel. Restart comp and go to R5E drivers under windows 8.1 and install second audio driver down 6.0.1.7373. Once installed you can install the windows 10 audio driver. I believe you are missing the sonic manager which is in the 8.1 driver 7373. But like I said you first need to disable windows updates prior to all this. You can enable it again after all finished. Worked for me
Maximus XI Formula, I9-9900k, Phantex Evolove X, Seasonic Titanium 850W, Custom loop PE360+SE360 Rad, G.Skill Trident Z F4-3200C14 32g, Nvidia Reference RTX 2080 TI, Samsung 970 EVO Plus 1Tb, Windows 11