Apparently, it's called a React Select but not sure.
Take for example this Language field in the Add Author form page:
Not being able to press HOME / END to edit what I type (typos, etc.) is very stressful.

It could have been so that the arrow keys and home and end and page up/down keys would have been reserved for the list navigation, but it's not the case.
The cursor focus is always in the text field but I cannot navigate freely.

I found the component: https://react-select.com / https://github.com/JedWatson/react-select

In their first example, HOME and END, ARROW keys, PAGE up/down keys, they are used for navigating the drop-down list.

It's an improvement over BB but still I would prefer to reserve those keys to fix my typing text.

Linked to React-Select Discussion #5291.