Custom widget not showing content

Hi, I created a custom widget using your docs. The widget is appearing correctly on your widget overview and on the edit page. I can also configure the form inside it (I used your hello world example and just renamed it). The problem is that the content doesn’t appear at the preview/published site. I have the feeling that maybe my template file isn’t found. I used both options: The preset tree (a tpl folder including a *.php file) and by defining it through

get_template_name

.
Is there any way to test/debug where the problem is?

My main widget file:

/*
Widget Name: divider widget
Description: An example widget which displays 'Hello world!'.
Author: Me
Author URI: https://example.com
Widget URI: https://example.com/hello-world-widget-docs,
Video URI: https://example.com/hello-world-widget-video
*/

class Divider_Widget extends SiteOrigin_Widget {

    function __construct() {
        parent::__construct(
            'divider-widget',
            'divider widget',
            array(
                'description' => 'A hello world widget',
                'help'        => 'https://example.com/hello-world-widget-docs',
            ),
            array(
            ),
            array(
                'text' => array(
                    'type' => 'text',
                    'label' => 'Hello world! goes here',
                    'default' => 'Hello world!'
                ),
            ),
            plugin_dir_path(__FILE__)
        );
    }
    
    function get_template_name($instance) {
        return 'divider-widget-template.php';
    }
}

siteorigin_widget_register('divider-widget', __FILE__, 'Divider_Widget');

function my_awesome_widget_banner_img_src( $banner_url, $widget_meta ) {
    if( $widget_meta['ID'] == 'divider-widget') {
        $banner_url = get_theme_file_uri().'/inc/custom-widgets/divider-widget/assets/banner.svg';
    }
    return $banner_url;
}
add_filter( 'siteorigin_widgets_widget_banner', 'my_awesome_widget_banner_img_src', 10, 2);

and my tpl:

<div>
test
    <?php echo wp_kses_post($instance['text']) ?>
</div>