I found the answer. When WordPress does a search query, if an orderby
is not specified, it adds this to the query
ORDER BY wp_posts.post_title LIKE '%yourterm%' DESC,
However, by default, ALM adds ‘date’ as the param to orderby, so wordpress does not try to sort by relevance on the title. I fixed my problem by changing my load more code to include a blank string for orderby:
echo do_shortcode('[ajax_load_more search="'.$search.'" offset="'.get_option('posts_per_page').'" orderby=""]');