Magento 2 : Join customer collection with custom collection

Question

\Block\Account\Message\Message.php

public function getAffiliateCustomerCollection()
        {
            $customerId = $this->customerSession->getCustomer()->getId(); 
            $affiliatecustomer = $this->_affiliateFactory->create();
            $customer = $this->_customerFactory->create()->getCollection();
            $collection = $affiliatecustomer ->getCollection();

        $joinConditions = 'customer_entity.entity_id = affiliate.customer_id';

        $collection->getSelect()->join(
            ['affiliate' => $collection->getTable('affiliate_account')],
            $joinConditions,
            []
        );

          $collection ->addFieldToFilter('customer_id',  $customerId);


         return $collection;
    }

This function not join the customer collection with affiliate customer collection and cannot identify the issue with joining these two collections