When a user is trying to purchase through PayPal Express Checkout first time if billing address is not correct the payment is declined and they are redirected back to Magento
In short, the site responds to this error appropriately and as said in the doc: when the buyer's first payment is denied, the buyer is redirected back to PayPal.
The problem seems to be linked to that redirection, which creates two orders in Magento (the two payment attempts — the first being denied by PayPal — are interpreted as two different orders/invoices. The buyer is charged once.).
Thus, in the backend (Sales > Orders) we can see for the same transactionid (PayPal) : 2 different billing address 2 different order ID numbers (magento) 2 different correlationid a « Completed » vs. « completed » payer address status (different syntax) an « IPN "Completed" » comment noticed on the first order
What could be done to solve this?
Thanks for helping!