JetPack Infinite Scroll on Search Results Page

I’m using JetPack Infinite Scroll on a new theme, and all is well. Except the search results page. By default, it didn’t work on the search results page but I managed to fix that by using the infinite_scroll_archive_supported filter.

function wh_infinite_scroll_support() {
	$supported = current_theme_supports( 'infinite-scroll' ) && ( is_home() || is_archive() || is_search() );
	return $supported;
}
add_filter( 'infinite_scroll_archive_supported', 'wh_infinite_scroll_support' );

However. When scrolling on to page two, the posts loaded are from the default loop as apposed to the second page of results from the search loop. It doesn’t appear to be maintaining the search query string. Has anyone seen this before and know of a solution?

Any help, greatly received.