Zetadocs uses the NAV record number to find related records.
If I understand correctly, the process you describe results in a new NAV record being created with a different record number. If this is the case, then you need to follow the advice on ZTN4282 to configure Zetadocs Mappings, otherwise Zetadocs does not know where to find the related documents you would like to be shown in the factbox of the new NAV record.
Regards,