When data exported from a matrix, Power BI exports the underlying data for the report. Please allow the ability to export the data as how it's laid out in the report.
I'm guessing this is the same for PBI service users as well (I use PBIRS) but exporting matrix from PBI report just drops ALL the data into CSV format which is not suitable for users who have no clue what to do with that data or how to group it up again in excel. Needs option to export matrix with data grouped (excel format), or even just export what is seen on the screen in that moment, without the ability to drill down/ungroup. I don't understand how this was created in 2017, and today in July 2020 it's is still outstanding, there are many "ideas" for matrix tables to be fixed. and how is this idea still in "new" status!
