certain domains can't be resolved in plex server
I have been running a plex media server for a few months and it was good till 2 days ago. The server is suddenly offline and disappeared from my account list.
I digged its logs and there are quite a few error entries regarding resolv thing such as:
HTTP error requesting GET httpsXXXXXXXXXX (0, No error) (could not resolv host: plex.tv) HTTP error requesting GET httpsXXXXXXXXXX (0, No error) (could not resolv host: ocspx.digicert.com)
sudo apt update works fine and the /etc/resolv.conf looks good as it just contains the default system generated name servers.
So just wondering is there anything currently wrong regarding DNS resolving of certain domains, which prevents my server login using my account ?