Hello Daniel,
This doesn't look like a standard login error, but rather an issue with the tenant's lifecycle.
To prevent millions of "phantom" tenants, Microsoft has a lifecycle policy for free tenants (which is what the aka.ms/TenantLifecycle link in your error refers to).
If there is no development activity on a free tenant for a certain period (e.g., 90 days), the tenant is automatically blocked for inactivity. This isn't a technical bug you can fix; it means the tenant itself has been disabled.