Custom domain not taking

Hello – I created a new version of an app to move from an internal version to a public version. Using the same URL didn’t take (despite removing it from the old app, it still resolves to it) so I created a new URL. I get the green check marks for validation, but when I return the share screen it never takes. Using the URL provides a security error (Firefox says: SSL_ERROR_ACCESS_DENIED_ALERT).