Davel, thank you.

I'm now able to see all the other computers on the network again. Why don't Microsoft fix this gremlin?

Although not working again after another reboot.

Davel's solution from:

Win10 suddenly stopped seeing other computers on network - Windows 10 Forums

does work though. Many thanks to him.

Thanks for the fix Borgus.

It didn't work to fix the original problem that I was looking for a solution for, which was the response to:
C:\WINDOWS\system32>net view
System error 1231 has...