Sharing an app to a External PowerBI Pro User which we provided from our Tennant

[Shawntwalter]

 I am having mixed results sharing PowerBI Reports and Apps outside of our organization.  

As a test, I have a yahoo email account that I granted a PowerBI Pro license in our tennant.

However, when I try to log in as that user, I get this error: 

AADSTS50020: User account 'shawnwalter@yahoo.com' from identity provider 'live.com' does not exist in tenant 'CATTLE FAX' and cannot access the application '871c010f-5e61-4fb1-83ac-98610a7e9110'(Microsoft Power BI) in that tenant. The account needs to be added as an external user in the tenant first. Sign out and sign in again with a different Azure Active Directory user account.

I have assigned direct access to the workspace to this user:

I have  gmail account which I set up the same way and it works great.  However, I notice that the  User Principal Name  has a live# prefix, not a mail# prefix.

This one worked fine sharing to an actual customer but like the yahoo account which fails, this one also has a mail# prefix: