WFM API 400 Error on Bulk Schedule Creation for External Agents

Ran into a weird issue today with the Workforce Management API when attempting to bulk-create schedules for external agents via our Premium App integration. The endpoint /api/v2/wfm/schedules returns a 400 Bad Request with the message Invalid schedule configuration whenever we include agents assigned to a specific custom work type. This occurs consistently in our US-West production org, while the same payload succeeds in our sandbox environment.

The payload structure adheres to the documented schema, including proper agentId references and availabilityType flags. However, the error persists even when isolating a single agent record. We are using the latest Genesys Cloud SDK for Python (version 145.0.0).

Is there a known limitation or hidden validation rule for external agents in the WFM module that isn’t documented? The error response lacks specific field details, making debugging nearly impossible without server-side logs. We need to automate this process for a client deployment, and manual entry is not viable at this scale. Any insights into why this specific work type triggers the validation failure would be greatly appreciated.