Row Level Security (RLS) on SQL Server data

Hi everyone, 

I am trying to give RLS a test but not getting anywhere when end users access reports & dashboards. Here's what I have set up, and done. 

Data: 

Data is coming from SQL Server through Reporting Services on-prem. The dataset contains sales data for districts in Western Australia, and contains two queries, Corporate Sales & Calendar.

I have added a new column UserID in Corporate Sales query in Query Editor and assign pbitest001 & pbitest002 based on random criteria. so now the rows in this dataset belongs to two users, pbitest001 & pbitest002.  I created a report, and in 2nd tab, i dropped a matrix, plotted user id and district fields on columns, and revenue figures on columns. basically this matrix will tell me what user i am able to see after applying RLS in the cloud.  I published the report in cloud, and dont' set up auto refresh, as yet.

PBI Service:

After publishing the report, I went to the dataset properties > security > RLS. Created a new rule in Corporate Sales which says [UserID] = "pbitest002", saved, and tested the role. It just shows the data for pbitest002 user. Sweet. 

 RLS DAX ruleRLS rule test

End User (PBITEST002)

When I log on to cloud using PBITEST002, i can still see data for PBITEST001. The column DaxUserName is a DAX measure, set to return value of Username(), which in this case returns current user name. 

Data view of logged on user (member, non admin)

Not sure why 002 user is able to see data for 001? I tried fully qualified column name in the DAX expression set in rules but does not work. What's more confusing is that the test works as expected. 

any ideas folks?

Thanks

Kaz