Hi @Luis Thank you for Posting your query on Microsoft Q&A.
From my understanding you are not able to connect to Azure SQL DB from SSMS with AAD integrated and looks like you have added the necessary users to the Azure AD Group for access to the SQL DB. Please let me know if my understanding is not correct.
The error Microsoft SQL Server, Error: 18456 indicates that the user trying to login to SQL Server Management Studio is invalid. It is usually related to an AAD user which is not added on SQL DB that you are trying to connect (User DB or Master DB) or that the AAD user is not the AAD Server Admin.
Please check that you have added AAD user in Azure SQL DB. You can follow the steps mentioned here
To create an Azure AD-based contained database user (other than the server administrator that owns the database), connect to the database with an Azure AD identity, as a user with at least the ALTER ANY USER permission. Then use the following Transact-SQL syntax:
CREATE USER <Azure_AD_principal_name> FROM EXTERNAL PROVIDER;
CREATE USER [bob@Company portal .com] FROM EXTERNAL PROVIDER;
CREATE USER [email@example.com] FROM EXTERNAL PROVIDER;
Azure_AD_principal_name can be the user principal name of an Azure AD user or the display name for an Azure AD group.
It won't be possible to invite the whole organization unless you put all your organization's users into that one group.