WFM Schedule Publish API returning 400 Bad Request on Agent Availability Overrides

Quick question, has anyone seen this weird error? with our automated schedule publishing process. We have a custom script that handles the final approval and push of weekly schedules every Friday at 16:30 CST. It has been running smoothly for the past six months on Genesys Cloud v2024.1. Suddenly, last week, the script started failing intermittently when trying to update agent availability overrides for a specific queue.

The API call is a simple PUT /api/v2/wfm/schedules/schedule/{scheduleId}/publish. The payload includes standard shift data and a few agent-specific overrides for training sessions. Most of the time, it returns a 200 OK. However, for about 15% of the agents in the payload, we get a 400 Bad Request with the error message: "Validation failed for object: 'overrides'. Error at: 'startTime'. Reason: 'Invalid date format'.".

The startTime field is being sent in ISO 8601 format with the correct America/Chicago timezone offset, exactly as specified in the documentation. We have double-checked the serialization logic in our Python 3.11 script using the official Genesys Cloud SDK. The dates are valid, and the same payload works if we manually paste it into the API console in the admin portal.

It seems like there might be a race condition or a caching issue on the backend during the bulk publish operation. We noticed that the failures correlate with agents who have pending shift swap requests that were approved just hours before the publish window. Could the WFM module be locking those agent records or expecting a different date format due to the pending swap state?

We are trying to avoid manually correcting these overrides every week. Has anyone else seen this specific validation error during bulk publishes? Any insights on how to handle agent records with pending swaps during the API publish call would be greatly appreciated.