"slide" Setting Doesn't Work

It seems like the "slide" setting doesn't work. In the documentation it says:

slide
Type: string
Default: 'div'
Description: Slide container type

However when I try to change the slide container type to a section element instead it remains a div. Also I notice that when I set the react key prop on each slide it doesn't work. The key prop seems to be getting set to something different to what I set.

Here is my example that is attempting to change the slide container type to a section element.
https://codesandbox.io/s/react-slick-playground-forked-jylzjv