Exactly: It's the Intel Iris Plus Graphics driver that comes along with an updated audio driver. Unfortunately, I cannot tell you which audio devices were updated. I assume that it was the "Realtek High Definition Audio(SST)", which is now at version 6.0.8850.1,
dated to 26th of November 2019.
I manually downloaded and installed the DCH driver from Intel's website at https://downloadcenter.intel.com/download/29674/Intel-Graphics-Windows-10-DCH-Drivers?product=80939.
I chose the exe installer, but it should work just as well with the inf file from the zip download.
All in all, the only drivers I changed from the retail image were:
- Intel graphics driver package, now version 27.20.100.8336
- NVidia graphics driver package, now version 27.21.14.5148
This worked! Was seriously stressing out over buying such an expensive machine with a basic problem like sound.
I went and manually downloaded and installed the Intel Driver. It updated the Intel Graphics Driver to 8336, and also the Intel Display Audio driver (under "Sound, video and game controllers" in Device Manager) to 11.1.0.16. I'd take a wild guess to say
that this was the problematic driver, as the "Realtek" driver wasn't touched at all (according to the event log).
My NVidia driver is still the original, but the problem is solved. Thanks for the insight!