CoAP Secure use x509 Certificate

Question

I execute CoAP Secure connect use "x509 Certificate" always disconnect, But CoAP Secure connect use psk is success. where did I get wrong in CoAP Secure Initial use x509 Certificate 
 Env: nRF52840, nrfconnect 2.1.0, zephyr 
 X509 Certificate data From /opt/nordic/ncs/v2.1.0/Modules/lib/openthread/src/cli/x509_cert_key.hpp 
 Server CoAP Secure Initial code: 
 # if IS_ENABLED(CONFIG_MBEDTLS_KEY_EXCHANGE_PSK_ENABLED)
// USE PSK
 otCoapSecureSetPsk( srv_context.ot, "123", sizeof("123"), "mypskid", sizeof("mypskid") );
 otCoapSecureSetSslAuthMode( srv_context.ot, true );
 
 otCoapSecureSetDefaultHandler( srv_context.ot, coap_default_handler, NULL );
 otCoapSecureAddResource( srv_context.ot, &light_resource );
 otCoapSecureAddResource( srv_context.ot, &provisioning_resource );

error = otCoapSecureStart( srv_context.ot, OT_DEFAULT_COAP_SECURE_PORT );
 if (error != OT_ERROR_NONE) {
 LOG_ERR("Failed to start OT CoAP Secure PSK. Error: %d", error);
 goto end;
 }

# else
// USE X509
 otCoapSecureSetCertificate( srv_context.ot, 
 MY_OT_CLI_COAPS_X509_CERT, sizeof(MY_OT_CLI_COAPS_X509_CERT),
 MY_OT_CLI_COAPS_PRIV_KEY, sizeof(MY_OT_CLI_COAPS_PRIV_KEY) );

otCoapSecureSetCaCertificateChain( srv_context.ot,
 MY_OT_CLI_COAPS_TRUSTED_ROOT_CERTIFICATE,
 sizeof(MY_OT_CLI_COAPS_TRUSTED_ROOT_CERTIFICATE) );

otCoapSecureSetSslAuthMode( srv_context.ot, true );
 
 otCoapSecureSetDefaultHandler( srv_context.ot, coap_default_handler, NULL );
 otCoapSecureAddResource( srv_context.ot, &light_resource );
 otCoapSecureAddResource( srv_context.ot, &provisioning_resource );

error = otCoapSecureStart( srv_context.ot, OT_DEFAULT_COAP_SECURE_PORT );
 if (error != OT_ERROR_NONE) {
 LOG_ERR("Failed to start OT CoAP Secure X509. Error: %d", error);
 goto end;
 }

# endif // end of IS_ENABLED(CONFIG_MBEDTLS_KEY_EXCHANGE_PSK_ENABLED)

Client CoAP Secure Initial code: 
 # if IS_ENABLED(CONFIG_MBEDTLS_KEY_EXCHANGE_PSK_ENABLED)
// USE PSK
 otCoapSecureSetPsk( m_otIntance, "123", sizeof("123"), "mypskid", sizeof("mypskid") );
 otCoapSecureSetSslAuthMode( m_otIntance, true );
 
 error = otCoapSecureStart( m_otIntance, OT_DEFAULT_COAP_SECURE_PORT );
 if (error != OT_ERROR_NONE) {
 LOG_ERR("Failed to start OT CoAP Secure PSK. Error: %d", error);
 return;
 }

# else
// USE X509
 otCoapSecureSetCertificate( m_otIntance, 
 MY_OT_CLI_COAPS_X509_CERT, sizeof(MY_OT_CLI_COAPS_X509_CERT),
 MY_OT_CLI_COAPS_PRIV_KEY, sizeof(MY_OT_CLI_COAPS_PRIV_KEY) );

otCoapSecureSetCaCertificateChain( m_otIntance,
 MY_OT_CLI_COAPS_TRUSTED_ROOT_CERTIFICATE,
 sizeof(MY_OT_CLI_COAPS_TRUSTED_ROOT_CERTIFICATE) );

otCoapSecureSetSslAuthMode( m_otIntance, true );

error = otCoapSecureStart( m_otIntance, OT_DEFAULT_COAP_SECURE_PORT );
 if (error != OT_ERROR_NONE) {
 LOG_ERR("Failed to start OT CoAP Secure X509. Error: %d", error);
 return;
 }

# endif // end of IS_ENABLED(CONFIG_MBEDTLS_KEY_EXCHANGE_PSK_ENABLED) 
 
 Client CoAP Secure connect: 
 
 void CoapsHandleConnected(bool aConnected, void *aContext)
{
 if(aConnected) {
 LOG_INF("Connected");
 }
 else {
 LOG_INF("Disconnect");
 }
}

static void send_provisioning_request(struct k_work *item)
{
 ARG_UNUSED(item);
 
 // CoAP Secure
 if( !otCoapSecureIsConnectionActive( m_otIntance ) ) {
 otError error;
 otSockAddr sockAddr;
 error = otIp6AddressFromString( "fdde:ad00:beef:0:b636:5398:5f11:85c4", &sockAddr.mAddress );
 if( error != OT_ERROR_NONE ) {
 LOG_INF("otIp6AddressFromString error.");
 return;
 }
 sockAddr.mPort = OT_DEFAULT_COAP_SECURE_PORT;
 otCoapSecureConnect( m_otIntance, &sockAddr, CoapsHandleConnected, NULL );
 }
 else {
 otCoapSecureDisconnect( m_otIntance );
 }

}