parameter value is not getting passed to DB adapter in OICgen3

Summary:

I am invoking an Oracle ATP connection in my integration. I want to fetch IDs from my database table for which I am writing a simple sql query. I have tried this query in Pure SQL as well as Perform an operation on a table/Select and then review & edit sql query.
SELECT EMAIL_GROUP_ID FROM schema.table WHERE OIC_INSTANCE_FLOW_ID = #parentOICInstanceFlowId

Passing the value to this parameter in mapper.
I can see the value getting passed in activity stream, Message received by Invoke. But message processed by invoke is not giving results as expected.
Running this same query in sql developer with passing the actual value of parameter parentOICInstanceFlowId, is generating correct results.