I recently added an Azure AD B2C tenant to an existing subscription.
Whenever I want to manage that tenant on portal.azure.com, I have to verify my account:
After clicking Next I can only select Mobile app from the dropdown to verify my account. There is no option to verify by phone.
Since this tenant is new, I first have to register it in Microsoft Authenticator by selecting Set up:
This brings up an error message without Correlation ID or timestamp:
There are no Conditional Access policies. In fact, I cannot dis-/enable MFA since this tenant does not have Azure AD Premium. Nor does the Azure AD tenant holding the subscription from which this AD B2C tenant was created.
MFA is only required when trying to manage the AD B2C tenant through portal.azure.com, not on other applications
How can I disable MFA for this AD B2C tenant? And why was it enabled in the first place?
If MFA cannot be disabled, how can I register my device or phone number?