Does not work on Amazee when fastly is serving content

Can confirm #3 is working for us at least.

I think this is a site-specific problem that shouldn't be resolved in this module, I would suggest using this snippet in settings.php instead:

/**
 * Tell Drupal to use the True-Client-IP HTTP header.
 */
if (isset($_SERVER['HTTP_TRUE_CLIENT_IP'])) {
  $_SERVER['REMOTE_ADDR'] = $_SERVER['HTTP_TRUE_CLIENT_IP'];
}

FWIW, I found that suggestion here: https://acquia.my.site.com/s/article/360055957214-How-to-configure-Drupa...