Channel manager: subsite: template composer - Unable to add any value to item "Banner"

1. Login to CMS
2. Navigate to channel manager
3. Select any sub-site channel >> click on open channel >> go to edit mode (where you see template composer)
4. Add or select banner

Expected - User should be able to add a banner link
Actual - Default value stays "common/banners/sustainable-wood-ipod-sound-system" and drop down does not show other options