EDIT

registrationId links are using in most cases the persistend identifier as href attribute. In one case the according Drupal path is being used.
Using the persistend identifier as link reference complicates testing since the user or test framework is always redirected to the production portal. In test environmets using the drupal path registration/{url encoded persistend identifier} would be the preferred solution

• Harmonize all registrationID links to make them really consistent
• Settings option to swith the portal from using the drupal path registration/{url encoded persistend http identifier} to using the persistend http identifier directly as link reference:
  • Form element: whitespace separated list of hostnames, , The persistend http identifier will directly br used as link reference if the host name of the server matches one of the strings.