403 on POST /api/v2/oauth/clients when setting division_ids

NICE CXone API & Integrations
1

POST /api/v2/oauth/clients

403 Forbidden.

Here’s the payload:

{
 "name": "bpo-client-1",
 "redirect_uris": ["https://example.com/callback"],
 "division_ids": ["12345678-1234-1234-1234-123456789012"]
}

Docs say division_ids is optional. I’m the admin. Why does adding that array break auth? Terraform is retrying but hitting the same wall.