"element options for developers" – not working

Hi
in Enfold-Settings ís this option:
“Show element options for developers”
– It is checked
– If i give an element a class this class does NOT show up in the HTML and therefore i cant adress it via CSS.
– I dont have any plugins installed which might cause that disfunction
– I can not give you access – website is on localhost

This is the content of my child-themes functions.php

<?php
/*
* Add your own functions here. You can also copy some of the theme functions into this file. 
* WordPress will use those functions instead of the original functions then.
*/
function enqueue_parent_theme_style() {
      wp_enqueue_style( 'parent-style', get_template_directory_uri().'/style.css' );
}
add_action( 'wp_enqueue_scripts', 'enqueue_parent_theme_style');

/* Proper way to enqueue styles and scripts
 */
function theme_name_scripts() {
	wp_enqueue_style( 'style-name', get_stylesheet_uri() );
}
add_action( 'wp_enqueue_scripts', 'theme_name_scripts' );

/* Activate Avia debug mode */
add_action('avia_builder_mode', "builder_set_debug");
function builder_set_debug()
{
	return "debug";
}

Why cant i access the CSS-class i gave to an element?

Kind Regards
Brita