Checkout with PayPal got 422 Error but charged successfully

I tried to purchase your books + hookpad bundle, and used “Checkout with PayPal” button to do so. I successfully completed checkout but when it went to redirect afterwards I received a 422 Error and a cheeky Rick Astley video. I was charged successfully, but I am unable to access my purchase. I am out the purchase cost and have nothing to show for it.

PS: getting rickrolled in the error message is quite off putting even if it was meant in jest.