ApplePay Web - sessionError {code:"unknown"}

Question

I am getting ApplePayCancelEvent with 'sessionError' right after successful apple pay session creation in my web app.

On the browser, it shows apple pay payment dialog with 'Payment Not Completed' message and the dialog got closed.

Following are the safari console logs:

[Log] getApplePaySession() for: https://apple-pay-gateway-cert.apple.com/paymentservices/startSession
[Log] getApplePaySession().onload() status: 200
[Log] ApplePayCancelEvent {isTrusted: true, sessionError: {code: "unknown", info: {}}, type: "cancel", target: ApplePaySession, currentTarget: ApplePaySession, …}

any clue.. folks ??