Could someone clarify why the Genesys Cloud Platform API returns a 400 Bad Request when our AppFoundry Premium App attempts to assign a contact list to a new outbound campaign via the /api/v2/outbound/campaigns endpoint? The integration handles multi-org deployments, and this specific failure occurs only when the contact list contains more than 50,000 records. The error payload indicates a validation issue with the listId, yet the same listId works perfectly in the UI and smaller test batches. We are using the latest version of the Genesys Cloud SDK for Node.js and have verified that the OAuth tokens possess the necessary outbound:campaign:write and outbound:list:read scopes.
The problem persists across multiple tenant environments, suggesting it is not an isolated configuration error. Our backend logs show the request body matches the documented schema exactly, including the required dialerType and contactListId fields. We have also confirmed that the contact list status is active and that no duplicate assignments exist. Given the scale of our deployment, manual UI assignment is not a viable workaround. Any insights into hidden rate limits or payload size constraints for outbound campaign creation via the API would be appreciated.