How do I fix 400 Bad Request on /api/v2/interaction/participants for agent wrap-up sync?

How do I fix the 400 Bad Request errors hitting the /api/v2/interaction/participants endpoint every Friday at 16:00 PT? The external WFM platform keeps failing when it tries to push wrap-up codes into the supervisor queue view.

Agent performance metrics stay blank until Monday and the floor is doing jack all during peak hours. The vendor says it’s a schema mismatch on SDK version 2024-09.1 but the console just returns a validation error.