[Resolved] Setup different domain per language (En/ZhCn)

Problem:
The client is setting up different domains per language for their WordPress site using WPML. The primary domain is set for English, and a subdomain is intended for Chinese. However, the client encounters an error message stating 'The domain you have entered is invalid' when trying to use the subdomain for Chinese. Additionally, there is confusion about whether using 'http://' instead of 'https://' could pose a security risk.
Solution:
We advised the client that the HTTP setting is automatically set on the left, and it should not be added twice. It's fine to enter the subdomain as 'zhcn.starrealties.com' without 'https://' in the site settings, as it might still redirect correctly on the front-end. We also suggested checking if the subdomain redirects properly by translating a page for testing purposes and then attempting to access the translation to see if the subdomain is being used for the secondary language. If issues persist, we recommended providing temporary access (wp-admin and FTP) to the site for further investigation, ensuring that all site details are kept private and secure, as outlined in our Privacy and Security Policy.

If this solution does not resolve the issue or seems irrelevant due to updates or different circumstances, please check related known issues at https://wpml.org/known-issues/, verify the version of the permanent fix, and confirm that you have installed the latest versions of themes and plugins. We highly recommend opening a new support ticket if further assistance is needed.