Hi @Jeff Jeffery ,
Thanks for reaching out and I can totally understand your concern and frustration here.
There has no change in Micrsoft Entra ID in terms of Azure AD B2C.
In Azure AD or Microsoft Entra ID , it is mandatory to provide Display Name while creating the user.
In Azure AD B2C, it is optional to collect "Display Name" attribute from user while registering the user.
Failed to received display name results in add "Unknown" in Name field in Azure AD B2C.
Azure AD B2C filters the data based on both Name and User Name (provided you need to search with full user name i.e the email address provided by user while registering the application).
in your scenario, there might be chances that user name search was not working for that particular time and it was taking some time if list is large)
I tried to test one case based on your scenario and able to filter user with User Name.
So I would recommend collecting the display name while registering the user in the future and search with the exact user name for now to get the user's details.
Hope this will help.
Thanks, Shweta
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