Problem adding custom domains to pages project

For Workes & Pages, what is the name of the domain?

carb-on.earth and all others in my account

What is the error number?

An unknown error occurred. Contact your account team or Cloudflare support: https://cfl.re/3WgEyrH. AND 8000018

What is the error message?

An unknown error occurred. Contact your account team or Cloudflare support: https://cfl.re/3WgEyrH. AND │ Error: error creating domain for project “9642729efe4c6e9a6d1c0be93c160a55”: You have already added this custom domain. Select another custom domain or check your project configuration. (8000018)

What is the issue or error you’re encountering

When I add custom domains to pages projects via Terraform and the interface, an error is returned during creation. Despite the error, the custom domain is created anyway. Thus, Terraform does not register the creation and retries, which results in an error 8000018, preventing the Terraform script from executing. The same happen when deleting a custom domain.

What steps have you taken to resolve the issue?

I can’t use terraform, so i’m creating manually and can’t rely on my CI/CD; hindering my development process and my future usage of cloudflare as a paid account.

What are the steps to reproduce the issue?

Add a custom domain to a Pages project.
Delete a custom domain to a Pages project.

Screenshot of the error