(1) Was all working well with networking before 21H1? Since it comes in so quickly through Windows Update (9ish minutes all told), I think I'd uninstall it, then let it come in again. Then let KB5003214 back in too, & I hope all will be well. That's at "START, Settings, Update & Security, View Update History, Uninstall Updates"...
(2) But I'm afraid I know little of networks having just this one computer. But I believe this 21H1 is working well with it because I can see my own computer in the Network folder of File Explorer after I switch to a Private profile...
I switch to a Private profile by clicking the Internet Access icon in the Tray & clicking for the Properties of my Wi-Fi connectoid...
In the page that opens, I set it to Private...
Note: If File Explorer is open to the Network folder, you must refresh the page to see the difference.