Session timeout is not respected when editing in Office (Office connector)

Summary

When attachments are edited in office
User is logged out after 10 mins and the session timeout defined in web.xml is not respected.
eg:

1. User has an Excel file attached as an attachment and tries to edit it in office.
2. User has this file open for more than 10 minutes and after 10 minutes when user tries to save the file user is required to login again to Confluence.

Steps to reproduce

1. Attach an excel file to a Confluence page
2. Edit this attached file by clicking 'Edit in Office' .
3. Try to modify the content and wait for 10-12 minutes
4. Try to save the file.

Expected Results
The file should be saved .

Actual result
User is required to login the file is not uploaded back to Confluence.

Workaround
No workaround
Notes
Issue persists on office 2016
Operating systems: Mac OSX and windows 10