SIte Builder removes image attributes and classes on custom widgets

Hi Alex.

Yes, I have the same problem with both Custom HTML Widget and SiteOrgin Editor widgets. See my screenshot.
https://pasteboard.co/JeL8DcO.png

Providing the whole code of my widget has no sense, because it contains some internal logic based on our blog posts. But I can share a “template” widget that has same problems.

in my functions.php

function custom_search_load_widget() {
    include_once(__DIR__.'/includes/ResourcesFeed_Widget.class.php');
    register_widget('ResourcesFeed_Widget');
}
add_action('widgets_init', 'custom_search_load_widget');

The Widget itself

// Creating the widget
class ResourcesFeed_Widget extends WP_Widget {
    function __construct() {
        parent::__construct(
            // Base ID of your widget
            'resources_feed',
            // Widget name will appear in UI
            __('Resources Feed Widget', 'resources_feed_domain'),
            // Widget description
            array('description' => __('Resources Feed Widget'),)
        );
    }
    public $args = array(
        'before_title'  => '<h2 class="widget-title123">',
        'after_title'   => '</h2>'
    );
    // Creating widget front-end
    public function widget($args, $instance) {
        echo '<img loading="lazy" class="test-class" src="https://autotis.ru/wp-content/uploads/2019/01/wp_1.png" />';
        echo '<img class="myclass" height="150" width="300" src="https://wp-cli.org/assets/img/wp-cli-logo-inverted.png" />';
    }
    // Widget Backend
    public function form($instance) {
    }
    // Updating widget replacing old instances with new
    public function update($new_instance, $old_instance) {
        $instance = array();
        return $instance;
    }
}

As you see widget outputs 2 images with additional attributes and classes. And they are missed on a page when I use this widget inside Page Builder.