Scroll bar disappears when Space Theme is set to Easy Reader Theme and Global Site Theme is set to Documentation Theme

Steps to Reproduce

1. Set Global Site Theme to Documentation Theme
2. Set Space Theme to Easy Reader Theme
3. Go to any page of that particular Space and you will notice that the scroll bar disappears like this
4. If you change the Global Site Theme to other themes (eg. Default Theme, Easy Reader Theme), the scroll bar is displayed correctly