Sucess page was redirecter to the empty cart page and created plugin

Question

Created plugin that overrides after SucessValidator

<?php

namespace DevAll\RedirectSuccessPlugin\Plugin\Magento\Checkout\Model\Session;

use Magento\Framework\Api\Search\SearchCriteriaFactory;
use Magento\Sales\Model\Order;
use Magento\Sales\Model\OrderRepository;
use Magento\Sales\Model\ResourceModel\Order\Collection;

/**
 * Class SuccessValidator
 * @package Vendor\Module\Plugin\Magento\Checkout\Model\Session
 */
class SuccessValidator
{
    /**
     * @var \Magento\Checkout\Model\Session
     */
    protected $checkoutSession;

    /**
     * @var \Magento\Sales\Model\ResourceModel\Order\CollectionFactory
     */
    protected $orderCollectionFactory;

    /**
     * SuccessValidator constructor.
     * @param OrderRepository $orderRepository
     * @param \Magento\Checkout\Model\Session $checkoutSession
     */
    public function __construct(
        \Magento\Sales\Model\ResourceModel\Order\CollectionFactory $orderCollectionFactory,
        \Magento\Checkout\Model\Session $checkoutSession
    ) {
        $this->checkoutSession = $checkoutSession;
        $this->orderCollectionFactory = $orderCollectionFactory;
    }

    /**
     * @param \Magento\Checkout\Model\Session\SuccessValidator $successValidator
     * @param boolean $returnValue
     * @return boolean
     */
    public function afterIsValid(\Magento\Checkout\Model\Session\SuccessValidator $successValidator, $returnValue)
    {
        /** @var Order $order */
        $order = $this->orderCollectionFactory->create()
            ->setPageSize(1)
            ->setOrder('entity_id', 'DESC')
            ->addFieldToFilter('status', ['eq' => 'complete'])
            ->getFirstItem();

        if ($order->getId()) {
            $this->checkoutSession->setLastOrderId($order->getId());
            $this->checkoutSession->setLastQuoteId($order->getQuoteId());
            $this->checkoutSession->setLastSuccessQuoteId($order->getQuoteId());
            return true;
        }

        return $returnValue;
    }
}

I think it was working but now I have an error

Fatal error: Uncaught Error: Call to a member function getMethodInstance() on null in /var/www/html/vendor/iways/module-pay-pal-plus/Block/Onepage/Success.php:64 Stack trace: #0 /var/www/html/vendor/iways/module-pay-pal-plus/Block/Onepage/Success.php(78): Iways\PayPalPlus\Block\Onepage\Success->isPPP() #1 /var/www/html/vendor/iways/module-pay-pal-plus/view/frontend/templates/paypalplus/success.phtml(21): Iways\PayPalPlus\Block\Onepage\Success->isPUI() #2 /var/www/html/vendor/magento/framework/View/TemplateEngine/Php.php(59): include('/var/www/html/v...') #3 /var/www/html/vendor/magento/framework/Interception/Interceptor.php(58): Magento\Framework\View\TemplateEngine\Php->render(Object(Iways\PayPalPlus\Block\Onepage\Success), '/var/www/html/v...', Array) #4 /var/www/html/vendor/magento/framework/Interception/Interceptor.php(138): Magento\Framework\View\TemplateEngine\Php\Interceptor->___callParent('render', Array) #5 /var/www/html/vendor/magento/framework/Interception/Interceptor.php(153): Magento\Framework\View\TemplateEn in /var/www/html/vendor/iways/module-pay-pal-plus/Block/Onepage/Success.php on line 64

how could it stopped working ?