get_search_query() not working with search queries with ampersand in it

get_search_query escapes the data for outputting to HTML. Can you try the following instead:

$argscontactdirectory = array(
        's' => sanitize_text_field( get_search_query( false ) ),
        'post_type' => array( 'expertarticle'),
        'orderby' => 'title',
        'order'   => 'ASC',
);