After trying to claim the server several times with no success, I deleted the server from my account thinking that perhaps there was some sort of conflict, so no, there isn’t a server in my account now, however it was there when the issue started, and it showed that it had been active a few hours earlier despite Plex not having worked for several days, which I found puzzling.
Regarding Preferences.xml; I deleted those four key/value pairs per the instructions I found on the Plex site. When I attempt to reclaim the server, those four values get re-created, but then the reclaim process appears to timeout and ultimate return a not authorized message. At present, all four of them have values. The current token starts with w and ends with u.