Gallery's permission system is designed to display the current domain name as it appears in G Suite while continuing to give access to users logged in with a previous domain name.
If you are seeing the previous domain name, you are likely seeing the warning message that appears whenever you are about to share with someone outside your organization.
Although Gallery's permission system recognizes that the current domain name and the previous domain name both belong to the same G Suite organization, you might still trigger this warning when you share a project to an email address with the previous domain name (for example, [email protected]).