Using a different domain per language and NGINX as a reverse proxy is not supported

Overview of the issue

If you are using an NGINX as a reverse proxy and then set up in a different domain per language, you will notice that the internal domain is being exposed.

Workaround

A workaround may be to remove filters on WPML_Include_Url.

add_action( 'plugins_loaded', 'disable_wpml_include_url' );

function disable_wpml_include_url() {
global $wpml_include_url_filter;

remove_filter( 'style_loader_src', [ $wpml_include_url_filter, 'filter_include_url' ] );
remove_filter( 'script_loader_src', [ $wpml_include_url_filter, 'filter_include_url' ] );
remove_filter( 'the_password_form', [ $wpml_include_url_filter, 'wpml_password_form_filter' ] );
}