I have the same board with no audio issues with windows 10 but I don't load the realtek drivers. I use the built in windows 10 drivers. Try removing the Realtek drivers and let windows find the built in ones.
Seems unlikely to be the bios then. Bad microcode was in the December 2017/ January 2018 time frame. Try upping the cpu core voltage by 0.05v. WHEA Event is a hardware error.
WHEA Event error was a error casued by an early bios cpu microcode fix for the Spectre exploit. It was fixed by a later cpu microcode. You have the latest bios?