embedded - external client does not see report

Probelm scenerio:

1. Client logs into legacy portal user his/her credentials
2. He/she clicks on Reports menu item
3. The request redirects the user to our new reporting portal that has an iframe with PowerBI workspace embedded
4. Reporting portal displays correctly but the PowerBI workspace displays error messsage "This content is not available"

Testing this internally we see the report, client does not.  Is this a licensing issue? Has anybody seen this behaviour?