[RTS] InvokeExtensionMethodRealtimeRequest/ InvokeExtensionMethodRealtimeResponse Not working in UAT

RTS API Behavior Issue

Summary

Describe the issue
We have created one RTS method extension on FnO side for the customer save and using that we created another one for searching the customer using the Chinese name but somehow this RTS method not working on UAT at all and only giving me Communication Exception error only in the response on the call of the API.

Version and Error Info
Commerce SDK Component: Commerce SDK / Ecommerce
Component Version: 9.56
Exception/Error Details:
{
"@odata.context": "https://scuob1gz3p697542003-rs.su.retail.dynamics.com/Commerce/$metadata#Edm.String",
"value": "ERROR: CommunicationException | Service response does not contain any data."
}

Screenshots

UAT : response:

PROD : response:

On Prod it the connection working and shows that the problem is with the method but on UAT it shows the Communication Exception error.

Start with the InvokeExtensionMethodRealtimeRequest/InvokeExtensionMethodRealtimeResponse call described in the issue and compare the UAT and PROD responses for Commerce SDK/Ecommerce 9.56. Reproduce the request in UAT and inspect the service response to identify why it returns CommunicationException; done means the extension method returns data in UAT or the environment-specific failure is documented with actionable evidence.