Hello,
Are you previsualizing it with Eclipse/Hana Studio or Lumira?
If you're using Eclipse, check if the generated SQL command is passing both input parameters
There should be a line with "Generated SQL:"
Double click it and check whether both PLACEHOLDERs ($$PARAM_1$$ and $$PARAM_2$$) are being passed on.
For test purpose, you can copy/paste that SQL command on a SQL console and manually add the missing param (if any).