Default option of a select input from shortcode ?

Hi,

I’ve come here because I fail to set a default ‘option’ for a select input in my form. I want to make it pass by the shortcode so my writers could choose the default option depending on the subject of the article. So I tried this method : https://contactform7.com/getting-default-values-from-shortcode-attributes/
But it doesn’t work.

There is what I’ve done :

In the form edition :
[select* services default:shortcode_attr class:cf-dp-services "Wireless Alarms|A02" "Security Phone|S03" "Locks|S08" "Remote Monitoring|R08"]

In the shortcode on an article about Remote Monitoring :
[contact-form-7 id="5488" title="Article Form" services="Remote Monitoring|R08"]

The entiere functions.php of my child theme :

<?php
add_action( 'wp_enqueue_scripts', 'theme_enqueue_styles' );
function theme_enqueue_styles() {
    wp_enqueue_style( 'parent-style', get_template_directory_uri() . '/style.css' );
    wp_enqueue_style( 'parent-style-shortcodes', get_template_directory_uri() . '/css/shortcodes.css' );
    wp_enqueue_style( 'parent-style-prettyphoto', get_template_directory_uri() . '/css/prettyPhoto.css' );
    wp_enqueue_style( 'parent-style-woocustom', get_template_directory_uri() . '/css/woo-custom.css' );	
    wp_enqueue_style( 'parent-style-responsive', get_template_directory_uri() . '/css/responsive.css' );	
}

add_filter( 'shortcode_atts_wpcf7', 'custom_shortcode_atts_wpcf7_filter', 10, 3 );

function custom_shortcode_atts_wpcf7_filter( $out, $pairs, $atts ) {
    $attr_se = 'services';
	
    if ( isset( $atts[$attr_se] ) ) {
        $out[$attr_se] = $atts[$attr_se];
    }
 
    return $out;
}

?>

But the forms keep the first choice (Alarms) as default option of the select input…

What did I wrong ?

Thank you in advance