CSS does not have any effect

Hi
on a new website (still in sandbox) all CSS changes we made do NOT have any effects.

1: We use a child-theme and it is activated
2: Yes – we did edit the correct CSS-file
3: WP latest
4: Enfold latest
5: PHP 7.x

Here the CSS

.logo { display: none; }
.box-2 {
	border: 1px solid #cccccc !important;
	padding: 12px !important;
	background: #ebebeb !important;
}

Here the element that has the class “box-2”

<div class="box-2"><strong>Engineering-Leistungen:</strong>
<ul>
 	<li>Anpassen und Optimieren der Komponenten</li>
 	<li>Planung von Automatisierung</li>
 	<li>Dokumentation</li>
</ul>
</div>

If i put in in “Quick-CSS”(Enfold-Settings-area) it works

We got in our childthemes folder 2 files
1: functions.php
2: style.css

This is the content of our 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";
}

What to do?

Kind regards max