Here it is !
I try numberposts whithout success, I don’t know if it’s important but for your information the select field list custom posts type.
add_filter('acf/fields/post_object/query/key=*my_field_key*', 'change_posts_order', 10, 3);
function change_posts_order( $args, $field, $post )
{
$args['numberposts'] = 7;
$args['sort_order'] = 'DESC';
$args['sort_column'] = 'date';
$args['orderby'] = 'date';
$args['order'] = 'date';
$args['post_status'] = 'publish';
return $args;
}
Thanks