CXone Studio DBConnector action returns empty result set despite valid query

Getting an empty result set from a DBConnector action in a CXone Studio script. The SQL query works fine in the database client, returning the correct customer record, but the Studio action returns nothing.

Here is the configuration:

Action: DBConnector
Connection: ProdCRM
Query: SELECT * FROM Customers WHERE CustomerID = {{Customer.Id}}
Output: CustomerData

The {{Customer.Id}} variable is populated correctly before the action runs. I verified this by logging it to a text file, and it shows the correct numeric ID. The DBConnector action completes without error, but the resulting list is empty.

I have checked the database connection settings and the credentials are correct. The table structure is simple, with CustomerID as the primary key. I have tried changing the query to use a hardcoded value, like SELECT * FROM Customers WHERE CustomerID = 12345, but the result is still empty.

Is there a specific way to format the SQL query for the DBConnector action? Or is there a limitation on the data types that can be passed? The CustomerId is a long integer in the database. I have also tried casting the variable to a string, but that did not help.

Any ideas on what might be causing this? The documentation is sparse on troubleshooting steps for this action.