We use PDT's cmd=_notify-synch
API to validate transactions when the customer is redirect back to our website after a payment.
We pass a "custom" value in our Paypal buttons with a customer id, and we expect to get this value back. This worked fine for the past 5 years.
Starting on or around 2018/10/19, the PDT API stopped returning the "custom" value that was passed in. This broke our payment flow.
Not sure if anybody else ran into this issue, and/or if there's a workaround or a configuration to change.