<?php
namespace VendorModulePlugin;

use MagentoCustomerModelResourceModelCustomerRepository;
use MagentoCustomerApiCustomerRepositoryInterface;
use MagentoCustomerApiDataCustomerInterfaceFactory;
use MagentoCustomerModelCustomerFactory;


class CustomerAfterSave
{
    protected $_customerDataFactory;
    protected $_customerRepositoryInterface;
    protected $_customerRepository;

    public function __construct(
        MagentoCustomerApiCustomerRepositoryInterface $customerRepositoryInterface,
        MagentoCustomerModelCustomerFactory $customerFactory,
    ) {

        $this->_customerRepositoryInterface = $customerRepositoryInterface;
        $this->_customerFactory = $customerFactory;
    }

    public function afterSave(CustomerRepository $subject,$savedCustomer)
    {
        //Get Customer
        $customerId = $savedCustomer->getId();

        $customer = $this->_customerRepositoryInterface->getById($customerId);
        $customer->setCustomAttribute('my_custom_attribute', 'test');
        $this->_customerRepositoryInterface->save($customer);
        exit;

( ! ) Fatal error: Maximum function nesting level of '256' reached, aborting! in /vendor/magento/module-customer/Model/ResourceModel/Address.php on line 58