Troubleshooting Custom Domain
You may encounter a custom domain name that is not verifying. The Customer states that they have added the records to their DNS settings days ago which is more than the time frame of 24 hours propagation.
The FIRST thing you need to check is the status of the DNS records entered into their settings using WHAT'S MY DNS website. https://www.whatsmydns.net/
Make sure to check the records.
In this case, they have an extra IP address where the domain name pointed to which is conflicting the records. They need to remove the extra IP in order for the system to verify the domain name.
Run another test and it should in the DNS checker to check the status and it should look like this,
There should only 3 records to show.
Then the domain name should be verified after refreshing in the custom domain page under ConvertKit.