WFM API 400 Error on Bulk Agent Update via ServiceNow

Does anyone know the strict payload schema for the WFM bulk agent update endpoint?

Our ServiceNow integration is failing with HTTP 400 when pushing schedule overrides. The JSON structure matches the v2.0 documentation exactly.

Using Python requests from a London EC2 instance. No firewall blocks detected.

Need help isolating if this is a validation quirk or a regional API latency issue.

The simplest way to resolve this is to check the timezone offset in the payload, as WFM APIs are strict about UTC formatting.

This usually causes the 400 error during bulk updates.