There still could be an issue that another driver is causing, whether it's related to another driver, software, or simply causing DPC latency (Which I know you checked).
Be sure you have the latest from Intel. Just verify the correct version for your OS:
https://downloadcenter.intel.com/product/71305/Intel-Ethernet-Connection-I218-VBack when I first got my Z170 board, there was a time where someone said how the Intel LAN driver was causing the issue and was a known issue. As soon as I updated it, the pops went away. To quickly check this, replicate your issue, then disable any Wifi or LAN drivers, and then try to replicate again. Or just update the driver.
Also check MEI drivers. Check all drivers!!!
🙂 Sometimes people mention some CPU settings in BIOS cause issues. May be worth checking online more. Eist or speedstep I've read.
Check if you have anti virus on/off, sometimes those can get in the way.
Question... how long did you let LatencyMon run for? Let it run for 30 minutes, then play on your computer, try to reproduce the audio issues while it's running, and check for any indications of audio issues. It should find something.
Otherwise I'd say backup every critical file/game saves etc, and reinstall Win10 carefully and install one driver at a time, check for audio issues for half a day or a full day, try to reproduce it, then install the next driver, rinse and repeat.
Z790 Asus Hero Maximus on 0816 BIOS (0914 and 1202 crashes for me on XMP I), Intel 13900k stock clock, Asus 4090 Strix OC edition, FF3D532G720 Teamgroup Ram running XMP I, 16gb x 2, Samsung 980 Pro 2TB x 2, Seasonic VERTEX GX 1200W, Win 11 Pro 64, Deepcool LS720 AIO, NZXT H7 Flow. Comfortably using Armoury Crate for updates/fan xpert.