I'm doing the integration with mercadopago (basic checkout) and the integration with the api of the notifications.
I did not have problems doing it, but we are experiencing many problems due to the behavior of notifications.
Users place an order on the platform and that is paid by MP. The external_reference is the id of the order.
When I checkout, I keep in my database the preference_id associated with that order.
Problem: We arrive for the same order and preference_id, different merchat_order_id, the first notification that indicates that it is paid and the second one that does not . Why? In the marketpayment panel they do not appear in dispute or canceled.
We do not use mercadoenvios.
I do not have much information other than this: link
When I create the preference at the checkout, I do not have the merchat order id according to the documentation, so I can not save it in advance to know which is the notification that is worth link