We're seeing this error show up in the logs and in our monitoring every so often.
(based on v3.17.6)
Paynl\Error\Api: PAY-404 - Resource not Found in vendor/paynl/sdk/src/Api/Api.php:155
Stack trace:
#0 vendor/paynl/sdk/src/Api/Api.php(80): Paynl\Api\Api->processResult()
#1 vendor/paynl/sdk/src/Api/Transaction/Info.php(51): Paynl\Api\Api->doRequest()
#2 vendor/paynl/sdk/src/Transaction.php(299): Paynl\Api\Transaction\Info->doRequest()
#3 vendor/paynl/magento2-plugin/Controller/Checkout/Exchange.php(326): Paynl\Transaction::get()
What connects them is the action being refund:received