Channel manager: surf & edit - Document does not open in edit mode for author

1. Log-in to CMS as author
2. Navigate to channel manager
3. Select any channel >> click on open channel >> click on "Edit content on this page"
4. Click on any content that is highlighted

Actual - Respective document opens in "view" mode in the same session.
Expected - Respective documents should open in the same session in edit mode.

Note - It happens only when the user is author.