1. The "hanging" sticky header lets your main menu and logo to always be at the top of the screen..
2. The transparent sticky header can be enabled/disabled from the option Sticky Header Behaviour - found in the local page's Vamtam options below the text editor.
To find the local page's Vamtam options click on "Edit page" and scroll below the content box:
3. Please note that the option "Sticky Header" found in Appearance > Customize > Header > Sticky Header must be "ON" in order to have sticky header working.