I had the same issue and poured hours upon hours of my time into researching the issue and attempting to find a solution…
After realizing that not a single thread offered any helpful insight, I decided to go against the eShop/PayPal suggested configurations.
The Solution? —
– I simply enabled the IPN/Auto Return on PayPal. All was fixed. All is well. All orders are immediately processed. All confirmation emails are immediately sent. All downloads are completed.
Hope this helps everyone who ran into the same problem.
