Just to sum up, what seems randomly to happen:
– client fills in the form
– client pays the ideal
– client receives error
– client receives stripe receipt of payment
– in stripe payment is created
– in stripe payment is marked as completed and paid
– in stripe the customer is added
– in stripe the metadata “custom field” is missing.
– in stripe the productId is mentioned
– On our site the order is viewable in orders overview
– On our site the order is marked as waiting/incompleted
– On our site we see the log error “Can’t find product with ID 0” on the failed payments