RequestReplyService Handling

Hi All,
I have a call to the target machine (MQ) in my service which needs synchronous data exchange. For this, we are using requestReply Service. The flow executes till this step. After the reply is received, we can see the values of the pipeline data while we are tracing it. However, once this is mapped to the canonical structure, we are not able to see the values being carried in the pipeline to the next step. I have ensured that the structures are similar(including the names of the fields which are mapped). I need help on this strange behavior for which i am not able to find a solution. Please suggest if any other settings have to be changed for the requestreply service to work. I have analyzed the other calls and they seem to be working fine. Thanks in advance.