TL; DR: Turn UEFI/BIOS Ethernet to Off fixes Intel wifi
My previous post expired after fifteen days. I have AsRock x470 Taichi motherboard with Intel AC-3168NGW wifi card. Ryzen 3950X. Worked perfectly on kernel 5.4 up to 5.7. Beginning with kernel 5.8 up to and including 5.10.2, upon boot Network Connections would show redline slash icon and no networks available (although the logon and connection setup would be visible under settings.)
Maddening because switching back and forth between 5.4 to 5.10 would restore then disappear the wireless connections with no other configuration changes. Comparisons between the two boots with “inxi -Fazy” or “journalctl -b | grep NetworkManager” would reveal not a damn thing wrong. Command line “sudo modprobe iwlwifi” and “systemctl restart NetworkManager” would do likewise nothing to restore wireless internet.
In frustration today, I boot into UEFI and select option “Disable Ethernet” reboot, and … BOOM, full strength wifi in kernel 5.10.2
Why would it do that? My system is now running stable without ethernet, but offer this in case some maintainer is working on iwlwifi. Thank you