Yup, one of the first things that I tried I also read log files until my eyes bled

but to no avail.
When I write a program I have a habit of repeating the error message in one or more logs, along with the circumstances that caused the error message to be thrown, Not so Plex.
I also wondered if the problem might not be associated with the need to connect to the Plex website, to the extent that I logged a ticket with my ISP ... that said, they assured me that all was well.
I haven't yet given up on Plex: I will continue to give it a try for the month or so.
And if I can impose on anyone to waste some time on assisting me, I have some log files that need reviewing by eyes less tired than mine