I upgraded OC 0.7.9 to 0.8.0. Per this post from @CaseySJ, I was hoping the updated SmallTree driver would get the top Ethernet port (en01) in my z390 Designare working again, but that didn't happen. (It was working fine in Mojave and Big Sur.)
In System Preferences, I added and deleted the port a couple of times, restarted the computer, and also tried renewing the DHCP lease. No change.
The port does appear in System Report > Ethernet devices.