Drupal 8 Clone Nodes

clone_nodes.info.yml

name: Clone Nodes
description: 'Creates clone of node.'
type: module
core: 8.x
package: Custom

clone_nodes.module

<?php

function clone_nodes_pages_entity_operation(\Drupal\Core\Entity\EntityInterface $entity)
{

    $operations = [];

    if ($entity instanceof \Drupal\node\Entity\Node) {
        $operations['clone'] = [
          'title' => t('Clone'),
          'url' => \Drupal\Core\Url::fromRoute('clone_nodes',['id' => $entity->id()]),
          'weight' => 150,
        ];
    }

    return $operations;
}

clone_nodes.routing.yml

clone_nodes:
    path: '/cnodes/node/{id}/clone'
    defaults:
        _controller: '\Drupal\clone_nodes\Controller\CloneController::clone'
    requirements:
        _permission: 'access content'

CloneController.php

<?php
namespace Drupal\clone_nodes\Controller;

use Drupal\Core\Controller\ControllerBase;
use Symfony\Component\HttpFoundation\RedirectResponse;
use Drupal\node\Entity\Node;

class CloneController extends ControllerBase
{

    public function clone($id)
    {
        $node = Node::load($id);
        if ($node === null) {
            drupal_set_message(t('Node with id @id does not exist.', ['@id' => $id]), 'error');
        } else {

            $nodeDuplicate = $node->createDuplicate();
            
            foreach ($nodeDuplicate->field_paragraphs as $field) {
                $field->entity = $field->entity->createDuplicate();
            }
            
            //edit title or something so you can find cloned
            $nodeDuplicate->save();

            drupal_set_message(
            	t("Node has been created. <a href='/node/@id/edit' target='_blank'>Edit now</a>", [
                  '@id' => $nodeDuplicate->id(),
                  '@title' => $nodeDuplicate->getTitle()]
            	 ), 'status');
        }

        return new RedirectResponse('/admin/content');
    }
}

Hello Marco
The EntityClone module proposed by Clemens doesn't seem to clone the referenced paragraphs.
So I created a module with your code and basically it works. The problem is that if I clone multiple times, the clones I already created will be cloned again. I can neither find the cause nor the solution for this problem. Can you help me?
Best regards Patrick