Cannot setup account despite being a root user with permissions

To setup new billing, I tried to follow the steps described at https://docs.aws.amazon.com/IAM/latest/UserGuide/tutorial_billing.html#tutorial-billing-prereqs:

1. Sign in to the AWS Management Console with your root user credentials (specifically, the email address and password that you used to create your AWS account).
2. On the navigation bar, choose your account name, and then choose Account.
3. Next to IAM User and Role Access to Billing Information, choose Edit.
4. Select the Activate IAM Access check box to activate access to the Billing and Cost Management console pages.
5. Choose Update.

Unfortunately, the step 2 is the last half-successful step. The whole page is of red messages like "Ihnen fehlt die Berechtigung zum account:GetContactInformation. Bitten Sie Ihren Administrator, die Berechtigung hinzuzufügen." (en: you don't have permission account:GetContactInformation). Correspondingly, I cannot activate "IAM Access".

Here is the policy I've attached to the root user:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "ThesePermissionsWillHaveNoEffectTillEndOfMigration",
            "Effect": "Allow",
            "Action": [
                "ce:Get*",
                "ce:Describe*",
                "ce:List*",
                "account:GetAccountInformation",
                "billing:Get*",
                "payments:List*",
                "payments:Get*",
                "tax:List*",
                "tax:Get*",
                "consolidatedbilling:Get*",
                "consolidatedbilling:List*",
                "invoicing:List*",
                "invoicing:Get*",
                "cur:Get*",
                "cur:Validate*",
                "freetier:Get*"
            ],
            "Resource": "*"
        },
        {
            "Sid": "ThisPermissionWillContinueProvidingAccessAsNormal",
            "Effect": "Allow",
            "Action": "aws-portal:ViewBilling",
            "Resource": "*"
        }
    ]
}

What I'm doing wrong?