Background of the issue:
This is a site operating on 18 country domains. The default language is en and the default domain is .com. I don't want to publicly show the content on the default WordPress language. I would like to show on .com only a domains tree. I am considering changing the default language of WordPress from reviell.com to something generic like wordpress-942459-3403990.cloudwaysapps.com.
Symptoms:
No specific issue or error message mentioned.
Questions:
Is it possible and safe to change the default language of WordPress from reviell.com to something generic like wordpress-942459-3403990.cloudwaysapps.com at this stage?
Since you're using different domains for each language, you'll need to make a few adjustments before changing the default language URL.
Firstly, configure the new domain in the same way as the other domains so it works seamlessly with different domains per language. Essentially, the new domain should also point to the same WordPress installation.
Once the domain is configured, you can migrate the site to the new domain and set up the Language URL Format under WPML->Languages->Language URL format.
If you plan to replace the domain URL directly through the database and hosting support, you can do that as well. However, you will still need to check and verify the Language URL Format under WPML->Languages->Language URL format afterward and make adjustments if needed.
After changing the domain URL, if you use WPML editors, WPML will prompt you to specify whether the domain is a staging site or has been moved to a new domain. Choose moved to new domain, and everything should work correctly.