Options escaping quotes

Ok, I think this code fixed the issue:

function filter_html_options( $new_value, $old_value ) {
    array_walk_recursive($new_value, function(&$value) {
        $value = stripslashes ($value);
    }); 
    return $new_value;
}

function plugin_init() {
    add_filter( 'pre_update_option', 'filter_html_options', 10, 2 );
}
add_action( 'init', 'plugin_init' );

Updated to 1.3 but problem still exists. But I changed my code to use wp_unslash and it works fine

I work currently on windows 10 with XAMPP installed, PHP version 7.1.6. WordPress 4.8.

Everything is basically copied from docs. Metabox and extensions are included directly in my plugin files. Metabox 4.12.2 and MB Settings Page 1.3

(I don't know how to format code because the editor here has no buttons)

the field:

    $meta_boxes[] = array(
        'id'         => 'brt-header-scripts',
        'title'      => __( 'Scripts before </head> tag', 'brt' ),
        'settings_pages' => 'brt-scripts',
        'fields' => array(
            array(
                'id'   => 'brt-head-scripts',
                'type' => 'textarea',
                'clone' => true,
                'sort_clone' => true,
                'add_button' => __('Add another', 'brt'),
                'attributes' => array(
                    'style'  => 'height:250px',
                ),
            )
        )
    );

the setting page:

    $settings_pages[] = array(
        'id'          => 'brt-scripts',
        'menu_title'  => __( 'Additional scripts', 'brt' ),
        'parent'      => 'brt-options', 
    );

Saving and new options works great. Thx.

The editor on the page looks like this:
http://tinypic.com/view.php?pic=2cr39yg&s=9

I'm using Windows 10, latest Chrome but I get the same problem in Firefox.

I get this in the console:
Uncaught ReferenceError: Backbone is not defined
at notes-common-v2.js:32
at notes-common-v2.js:158
admin-bar-v2.js:2 Uncaught ReferenceError: _ is not defined
at admin-bar-v2.js:2