@nikos_lapokonstantakis Did you ever figure out a solution? Having the same problem calling https://apple-pay-gateway-cert.apple.com/paymentservices/merchant using mTLS in my AWS environment. I'm just using a simple httpclient.. builder.Services.AddHttpClient("ApplePayClient") .ConfigurePrimaryHttpMessageHandler(() => { var handler = new HttpClientHandler { ClientCertificateOptions = ClientCertificateOption.Manual, ClientCertificates = { applePayCertificate } }; return handler; }); Have no issues on local and struggling to find a solution. Feel like there's a setting in AWS which is causing an issue but any suggestions would be great.