Your theme is modifying the search query and removing the Download Manager post type from the query. That’s why the search result was empty.
I have hooked the following custom function with pre_get_posts to override it which fixed the issue.
function add_wpdm_in_search( $query ){
if ( $query->is_search ) {
$post_types = $query->query_vars['post_type'];
if( isset( $query->query['post_type'] ) && $query->query['post_type'] == 'wpdmpro' )
$post_types = array('wpdmpro');
$query->query_vars['post_type'] = $post_types;
}
return $query;
}
