Windows 10 networking is not nearly as reliable as previous Windows. I have had to perform the Windows 10 network reset on brand spanking new hardware as well as virtual machines. It is quite possible everything was correct with QubesOS, but Win10 itself was broken. Luckily, the Windows 10 network reset is almost always a totally safe operation. WiFi passwords are not lost for instance. But it is so annoying because all the normal network troubleshooting is done before you suspect a “Network reset” is needed. Reboot Required 
Eliminate problems with the special darkened Windows security attention graphics mode - oh what is that screen called:
- Until it is figured out, from an elevated admin prompt,
userAccountControlSettings.exeand turn it all the way down to “Never notify”. - Use
control.exe ncpa.cplfrom an already elevated prompt.
One change i have seen relatively recently is that I now have one item in devMGMT.msc showing with a yellow mark - it is “XP0001 XENBUS CONS”, but everything seems to work ok. Definitely have network connectivity and have restarted countless times do Windows updates and tests. However, i started setting these machines up in March of 2021. Currently, running Win10 20h2.
My Windows machines are their own template and the “Run in debug mode” checkbox is checked.
One thing i just noticed is that there are 9.0.0 drivers from 2019 mentioned in your article and much newer drivers from less than two months ago - 2021-12-19. I am still using the 2019 drivers.