Predictive Queue Creation 400 Error Despite Valid Payload

I’m completely stumped as to why POST /api/v2/routing/predictivequeues returns 400 Bad Request with error_code: invalid_queue_strategy when the payload matches the 2024-01-01 OpenAPI spec. The strategy field is explicitly set to skills_based and the member_list references valid user UUIDs, yet the Genesys Cloud API rejects the request before hitting our ServiceNow Data Action for ticket creation. Has the schema changed silently for ap-southeast-1 regions?