I am using OAuth 2.0 Authorization (marklogic-xquery-oauth2) with MarkLogic 11.1.0.

For a request to the app-server with application-level authentication and default user as oauth-anon (details in the linked github repo), ID of the user name returned by xdmp:get-request-username doesn’t match the user ID returned by xdmp:get-request-user.

Also, no user can be found in the Security database with the user ID returned by xdmp:get-request-user.
User corresponding to the name returned by xdmp:get-request-username does exist in the Security database.

Can someone please elaborate on this behaviour?