A group of Microsoft Products and technologies used for sharing and managing content, knowledge, and applications.
Here is a potential powershell solution to this problem.
https://www.benstegink.com/delete-unlock-sharepoint-document-locked-another-user/#.XSICgOhKjD4
I think the advice here is clear. Never tell MSFT that the problem is solved until you get the answer you need. They are ignoring this thread because at one point in time MSFT was told the problem resolved itself. They are now ignoring this thread even though it is still very active.