1. Go to the Backup tab via UI and check 'Exclude new repositories'.
2. Create a repository via REST.
Now see in the UI -> Backups tab that ALL the repositories were moved to the Exclude tab.
3. Create another repository via REST
Now all the repositories are duplicated in the Exclude tab.
Now if you try to delete one of the repositories which is duplicated you will get 'Failed to read object from stream' error.