PMS not showing in web app even when web app is served from the very same PMS

Plex Media Server
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3

In the meantime I actually did two things in order:

  1. Reset password
  2. Edit Preference.xml

With regards to (2), I could not find key PlexOnlineHome, but I removed the other three entries.

I also setup a SSH tunnel to be able to connect to may PMS instance via IP address 127.0.0.1.

Using http://127.0.0.1:32400/web I was able to connect to my PMS instance; I would see my media right away, but then under PMS > Settings > General the warning This server is unclaimed and not secure shows up and when I click on CLAIM SERVER I’m getting error

There was a problem signing in to Plex.

If I cannot claim my own PMS then I’m stuck with just a different problem.