The custom domain for your GitHub Pages site is pointed at an outdated IP address

[gradyrobbins]

gradyrobbins.com is improperly configured

The custom domain for your GitHub Pages site is pointed at an outdated IP address. You must update your site's DNS records if you'd like it to be available via your custom domain. For more information, see DeprecatedIPError. We recommend you add an A record pointed to our IP addresses, or an ALIAS record pointing to gradyrobbins.github.io.

[gradyrobbins]

It can take up to an hour for your site to become available over HTTPS after you configure your custom domain. After you update existing DNS settings, you may need to remove and re-add your custom domain to your site's repository to trigger the process of enabling HTTPS. For more information, see "Managing a custom domain for your GitHub Pages site."

[gradyrobbins]

You need to add two “@” type A records that point to the GitHub ips 192.30.252.153 and 192.30.252.154 and one “www” CNAME record that points to your USERNAME.github.io url

the Github domain(-s?) threw an error

192.30.252.153
192.30.252.154

this doc offered a different set of IP's that worked for me.

Mine ended up looking like this:

• 4 type A records that point your apex domain to the IP addresses for GitHub Pages. the GitHub ips:
  185.199.108.153
  185.199.109.153
  185.199.110.153
  185.199.111.153
• 1 “www” CNAME record that points to your USERNAME.github.io url