Welcome to the community @FrozenAssassine
Looks like your DNS AAAA record for IPv6 is pointing at a github server and not nginx. The --nginx plugin option you chose only works with nginx.
Your DNS A record points to an nginx server so your IPv6 address is probably just wrong. Best to update it for the correct address and try again.
Many ways to determine that address but one if by running this command
curl -6 https://ifconfig.io
If that fails then you probably don't have IPv6 enabled so should then remove the AAAA record (or fix IPv6)