The name of a Submissions Archive document is changed. Why is the original name of the document rather than the updated name shown for the document in the Submissions Archive Viewer?
This is working as expected. The Submissions Archive Viewer does not show the name of the document as it is in Vault. It shows the name of the document at the time of import because the same document could be used in multiple submissions with different names, and the document name as it is in each Submission needs to be shown. This also allows Submissions Archive cross-document links to work in Vault if the document contains any cross-document links.
Vault Documentation: Viewing Submissions (RIM)