If your I219V7 works in Big Sur but not in Parallels then it is a configuration problem in Parallels.Big Sur works perfectly and the network runs smoothly.
is detected as: Intel I219V7 PCI Express Gigabit Ethernet ...
You must install the RealtekRTL8111.kext and add it to your config.plist.So I bought a Realtek RTL8111E on PCI-E to try to see if I could fix the problem but BIGSUR doesn't detect it.
How can I install it?