Switched to custom domain but test still sends auth0 domain as callback

We have a custom domain setup and have non-development keys for Google social. The callback has been set there to the custom domain as well. However, when hitting the “Try Connection” button for Google, the error “Error 400: redirect_uri_mismatch” appears. Looking at its details, the redirect_uri is still using the auth0.com URL. Gave it several hours, still happening.