POST /api/v2/conversations/cobrowse 400: traceparent header ignored in session creation

Getting a 400 Bad Request when trying to kick off a cobrowse session programmatically. The payload seems fine, but the trace context isn’t sticking. We’re injecting the traceparent header into the request for OTel correlation, but it’s vanishing by the time it hits the cobrowse service. Here’s the cURL:

POST /api/v2/conversations/cobrowse
Headers: traceparent: 00-abc...
Body: { "type": "cobrowse" }

Any idea if that endpoint even supports header propagation?