Custom Search only for my Custom Taxonomy Page – data

You can try modifying your query using pre_get_posts filter.

 function mod_query() {
    if ($query->is_main_query() && !is_admin() && is_search()) {

    // test print queried search terms
    print_r( $query->query_vars['s'] );

    $search_terms = $query->query_vars['s'];
    $search_terms = preg_replace('/\s+/', '+', $search_terms);

    // test print after replacing spaces with +
    print_r( $query->query_vars['s'] );

    // if all going well you can change the vars again
    $query->set('s', $search_terms);

    }
 }
 add_filter( 'pre_get_posts', 'mod_query' );

You may need to modify it to get working. But, this can lead you to a solution.

I am not sure – but you may need to change the name=”motion” to name=”s” as default \
Wordpress name for Search field. I will keep an eye on this thread.