Can anyone clarify WFM Campaign Sync Errors for Migrated Zendesk Agents?

Can anyone clarify why our WFM campaign assignments are failing for agents migrated from Zendesk? We are moving a support team from Zendesk to Genesys Cloud. In Zendesk, scheduling was handled via simple CSV imports and direct ticket assignment. Now, trying to map those agents to Genesys Cloud WFM campaigns using the POST /api/v2/wfm/scheduler/v2/config/campaigns endpoint returns a 400 Bad Request with error code WFM_CAMPAIGN_INVALID_AGENT_ID.

The agent IDs look correct in the UI (v10.4.0), but the API rejects them. We suspect the issue stems from how Zendesk agent profiles mapped to Genesys Cloud user accounts. In Zendesk, we had separate “agents” and “end users.” Genesys Cloud seems to require a specific user_type of agent with routing_enabled set to true for WFM to accept the ID.

Our migration script set routing_enabled to false initially, assuming we’d enable it later. Should we update the user profile first via PATCH /api/v2/users/{id} before attempting the campaign assignment? Or is there a specific WFM configuration setting we are missing that mimics Zendesk’s more flexible assignment model?