Migrating domain from old to new account throws 404 error

I looked up the domain name and I see domain was added to the current account only 30 minutes before posting this message. As you can see in the client area when you check the Health Check section for this domain: it can take up to 72 hours for a new domain name to start working everywhere. This is due to DNS caching. And yes, for these purposes: a domain that was removed from one account and added to another is effectively a “new” domain. So please have patience. Nothing is wrong and your website will start working automatically for you too. But that can take some time, up to 72 hours but usually much less.