It's okay now.
I got all huffy and puffy and bent out of shape, and left.
When I came back a little bit before noon (central time; 11:00 a.m. mountain time), I fussed and fretted and finally went to "network connections" on this computer.
Finding that, I looked at "tools."
Microsoft did its diagnostic thing, and came up, "no problems detected."
HOWEVER, it gave me a rather, uh, unusual option, "repair it anyway."
I chose that option, and the connection's been working slick as Crisco oil since then.
But a new question: if no problems were detected, how come it obviously repaired something?