Spacing utilities can also be triggered at various breakpoints.
This is disabled by default. Enable block variable $utility-spacing-responsive or add to class filter in your page SASS manifest to enable locally (For that page), or overrides.scss to enable globally. (More info)
Adding this class to an element with a spacing utility means that if that element is also the last child element of its parent, the spacing won't be applied. This is almost exclusively used for programatically generated elements with margins, where the last element in the set needs to be margin free.