You can see the title of the report of which you are marked as Duplicate
Steps to Reproduce: 1. Report a bug to a team 2. Now that team marks your bug as 'Duplicate (#Report_ID).(but does not shares the report with you) 3. When that bug is marked as Resolved then you can see the title of that bug at https://hackerone.com/settings/reputation/log
This is clearly a lack of authentication as unless the bug is not shared or it is not public you should not be allowed to see any of its content.