How long did it take before things returned to normal for you? Do you, by chance, integrate with Fiserv? My team is also experiencing this exact issue now, apparently. Our merchant validation expired in our production environment, and understandably Apple Pay stopped working. After successfully re-verifying, this issue began. The codebase had not changed at all, and the requests sent to Apple, that result in this error response, seem to be identical to the requests that receive a success response. And, as was reported in this thread, it seems to always work fine when attempting the transaction a second time. It's been over 24 hours since we finished that successful re-verification, but this still occurs.