Backend feedback - compliance report - DOI registration

[agentilb]

https://backend.dev.scoap3.org/admin/articles/compliancereport/4683535/change/?_changelist_filters=article_id__report__check_doi_registration_time__exact%3D0
-> "DOI registration date not found."

If I compare the same article on legacy, the system doesn't show an error on DOI registration date.
Is it because it is not checked on legacy either?

We should be able to see the number of hours difference in DOI registration time, as we do in legacy.
Example: "Arrived 25 hours later then creation date on crossref.org."
(this is ok to display this information in the detail of the compliance report).