Focus Not Obscured
This information relates to criterion 2.4.11 Focus not obscured, which states:
When a user interface component receives keyboard focus, the component is not entirely hidden due to author-created content.
This success criterion is new for WCAG 2.2. It is aimed at users who navigate by keyboard or otherwise need to see where the focus is on the page.
When navigating by keyboard, the user should be able to see, at all times, which item is in focus. This connects with 2.4.7 Focus visible, but rather than being about the actual focus indicator, this one is about whether any content obscures the focus from view.
If you stick to regular HTML and don't use sticky headers or footers, or anything else that can cover an entire item, then you should not fail this criterion. However, if you use sticky headers or footers or have items that cover parts of the page, you will need to ensure that at least part of every focussable item can always be seen.