In Store settings › Custom domain, a whole domain such as example.com is connected with an ALIAS record (also called ANAME or CNAME flattening), or with an A record where the DNS provider has no ALIAS. A subdomain such as shop.example.com uses a CNAME record. These records change only where the website is: MX and the domain's other records stay as they are.
The Custom domain page updates by itself when Magpie's background check finds the records or gets the security certificate, and shows Live when the domain is ready.
Once the domain is live, pages at the Store's Magpie address open the same page at the domain, so links people already have keep working. Carts and checkouts started at the Magpie address finish there. Turn off Magpie address on the Custom domain page to show the Store at both addresses. Search engines are told the domain is the Store's address, and the Store's sitemap lists its pages there.
A live domain now stays connected when a check cannot find its records. The page shows what the check found, and the team's admins get an email if it lasts 24 hours, and once more after 7 days. Before, the domain stopped showing the Store at its next daily check.
Fixed connecting an address again after it was disconnected.