Is my IP address black listed?

On the latest version of PMS on Mac Mini. I was getting an error when checking for updates saying update failed and to manually update. Clicking the link to manually update takes me to the downloads page but it the page fails to loads the available versions and said an error occurred. When I tried to access my server, it says server was unclaimed and when I clicked on the Claim icon, nothing happened. Tried restarting PMS and my Mac Mini with no success.
Turned on my VPN and it all worked fine, I could update and also claim my server. Turn off my VPN and the update page fails again.

There are no IP ranges blocked of regular, domestic internet connections.
(unless you happen to live in the datacenter of a certain German hosting provider)

My first idea would be that you have an issue with DNS resolution, if you don’t use the VPN.
I’d try the alternate DNS servers recommend in here: https://support.plex.tv/articles/206225077-how-to-use-secure-server-connections/#toc-4

Thanks for the reply.
I’ll try a router reboot this evening to see if it has any impact before considering a change of DNS.