SAP BW Via MDX

First time poster, long time browser

I'm connecting PowerBI Desktop to our SAP BW. I'm able to successfully use the data browser that comes up, but it's extremely slow. As a result, amongst some other benefits, I've decided that MDX queries might be the better way for me to go.

Below is a sample syntax that works flawlessly via the SAP transaction MDXTEST, but it throws an error in PowerBI

Any help to a BI noobie would be greatly appreciated.

SELECT
NON EMPTY
  { Except( [4IV1MKFTHL2RJCNHHIZTMGD3L].Members,
            { [4IV1MKFTHL2RJCNHHIZTMGD3L].[4IV1MKV6JIA6KLQDT74I6KAJ5],
              [4IV1MKFTHL2RJCNHHIZTMGD3L].[4IV1ML2V2GVW389TZ16UGM98X],
              [4IV1MKFTHL2RJCNHHIZTMGD3L].[4IV1MLPWNCP0N3W6GJDVAS5E9] } ) }
ON COLUMNS,
NON EMPTY
  { Order( [0MATERIAL__YBV1PHE2],
           [0MATERIAL__YBV1PHE2].[20MATERIAL__YBV1PHE2],
           ASC ) }
ON ROWS
FROM
  [YUB6AUPGI/YUB6AUPGI]
  SAP VARIABLES [YCALMO_M] INCLUDING 01.2019