RLS, B2B and Analysis services issue

Hi

I have my azure subscription in DomainA.com and my Powerbi.com in a DomainB.com.

I have :

1. Created a guest invite to user x.y@domainB.com in domainA.coms Azure AD.

2. Then I have tried to add  x.y@domainB.com to a role in Azure Analysis services (domainA.com)

3. I cannot find x.y@domainB.com but I find x.y_domainB.com#EXT#@domainA.onmicrosoft.com

4. I add this account to the role 

5. I cannot see any model in either excel or PowerBI. 

I can put a manual entry in the analysis services role and that works. But I would like to use AAD groups in the role and handle all administration within AAD. Does anyone have any ideas?

Thanks in advance!