SmartLink works perfectly for over two years, but now cannot connect

Given: Flex 6400, purchased summer 2019 and SmartLink'ed. Used regularly for CW, SSB, FT8, most of the time using a Maestro as the front end. Running 3.2.39. I have remote power on/off capability.

I'm currently remote and the connection to the radio fails. Here's the symptoms. It was working one day and just stopped working.
1) I see my radio in the "Select Radio" list on the Maestro
2) I select it and hit the "Connect" button
3) I select "v3.2.39" and hit the "Run" button
4) "Loading"
5) Meters show up, but no
5) "Client connected from IP" with my IP
6) "Radio disconnected. Waiting for radio/network." with countdown
7) I get another "Select Radio" list, this time without the radio I want.
8) After a minute or so, the radio shows up again.

Other clues:
1) There is another radio in my "Select Radio" list that belongs to a friend. I can connect successfully to it.
2) When on the "Select Radio" panel with my radio selected, there is no "Disconnect" button. When I select my friend's radio, I do see the "Disconnect" button.
3) When on the "Select Radio" panel with my radio selected, the "Info" button does not include the line that includes TCP Port and UDP Port. If I have my friend's radio selected, the "Info" button does include TCP Port and UDP Port.

What I've tried:
1) Power down, unplug supply, reapply supply, power up.
2) Restart cable modem.

I'm 1000 miles away from my radio and would really like to get it back on the air. I do have a willing non-ham that has access to the shack and network. Anybody have any suggestions?