Local plex server shows up as remote only, with remote settings applied when using Plex Web.

@gusvjr said:
So I decided to see whether the problem was isolated to my router and plugged in the network cable directly from my modem to my PC, logged off plex web/app, reset my connection to use my ISP’s settings, rebooted modem, rebooted PC, and the server still displays as Remote. That means it’s not the router at least, I assume? I’ve no firewall on, either.

The 406 error is a clue here

Connections] Excalibur connected at http://137.217.15.101:32400/
[Servers] Waiting for initial servers = [Loopback]
[Connections] Testing connection for JT01 at https://24-xxx-xx-xxx.e63690623a014174a3a06b450ce3e5c4.plex.direct:32400/
[Connections] Excalibur connected at http://24.xxx.x.xx:32400/
Failed to load resource: the server responded with a status of 406 (Not Acceptable)
[Connections] [Loopback] is unavailable at http://127.0.0.1:32400/ (Status 406)
[Connections] All connections to [Loopback] failed

It is looking like the issue identified recently and summarized here
https://forums.plex.tv/discussion/comment/1171939/#Comment_1171939

This stops loopback from being used.