Paginated Report with Tabular Model source and a parameter included - PARAMETER WONT WORK

We are producing paginated reports using DAX from a SSAS Tabular model and they seem to wokr, though frankly the DAX involved makes my brain hurt.

We have produced parameterised MDX reports in the past from MD cubes as opposed to Tab models and those also seem to wokr though params and MDX are frnakly a complete pain and fraight with all manner of issues. have you confirmed the MDX works with the parameter in an SSMS MDX query window onto the tab model?