If you accessed MVE using ADFS, then the Log out button does not appear on the MVE home page. The MVE session ends only if you close the MVE page or the MVE session is idle for more than 30 minutes. If you try to access the MVE URL after 30 minutes of inactivity, then you are redirected to the ADFS login page.
Note: If you accessed MVE using your localhost MVE credentials, then the Log out button still appears on the MVE home page.