Error 400 - Azure Analysis Service XMLA endpoint on Report Builder

Hi all,

When connecting to my workspace and dataset I am receiving an error 400. Connection string is:

DataSource=powerbi://api.powerbi.com/v1.0/[tenant name]/[workspace name];initial catalog=[dataset name]

XMLA endpoint and Paginated Reports are enabled on the Admin portal.

Response received: 

The remote server returned an error: (400) Bad Request.

Technical Details:
RootActivityId: ad4ccc26-0685-47a8-995f-ede2946a210a
Date (UTC): 5/30/2019 4:03:56 PM

Am I missing something?

Many thanks!