Workflow - CommServDBQuery cannot use temp tables?

Hi

Does anyone know if there are any restrictions in the workflow engine regarding the use of temporary tables in the CommservDBQuery activity? In the SSMS the query works fine.

When I run the above SQL query in the debug mode, I don’t get any output:

I also tried to use a table as variable, which did not work either.

The workflow engine runs on a dedicated server. Could this cause the issue?

Thanks for your inputs

Michael