This is an accepted solution.
Hilary here from Shopify. To resolve the error you are receiving, you will need to contact our Support team directly to finish connecting your domain. This is because we will need to access your account in order to resolve this issue. While we’re not able to provide account-specific support via the Shopify Community at this time, we’d be happy to continue assisting you through live chat, email, or callback. Please visit https://bit.ly/3cJkx8V and log in to your account to create a support request.
Our team will request some further information from you regarding your domain name, and will be happy to help get this resolved with you.
Since this is the next step I've marked this reply as the solution for the benefit of others who may discover this topic. Thanks!