Creation of Azure Active Directory B2C tenant failed to create without any explicit message

A few weeks ago I created an organization and added users and a domain name. Today I want to create an Azure Active Directory B2C tenant, however it failed to create it. The validation was correct but the creation of the tenant failed without any specific reason. Looking at the activity log, I discovered a more specific reason being that I do not have the correct permissions. However, I’m the owner of the subscription in Azure RBAC as well as Global Admin in Azure AD.

Anyone an idea what might be going wrong?