Missing metadata at Crossref

We use CrossRef XML Export Plugin in connection with the registration of DOI at Crossref. Therefore, we were convinced that all references entered as metadata would also be registered with CrossRef. Unfortunately, that is not the case. Is it a mistake on our or on your part, or should we contact Crossref?
Our current version is
The informations is taken from Crossref’s Participation Reprots page: Participation Reports
Niels Erik