request_body_timeout

The request body did not arrive in time; nothing was forwarded.

HTTP 408. Nothing reached the broker.

Likely cause: The client sent the body too slowly (inbound provider webhooks allow 10 seconds by default).

What to do: Send the whole body promptly, then retry.

Retry: Yes. Nothing happened (or it was a read), so repeat it, after Retry-After when present.

Listed under Requests and validation in Errors. Send the error’s requestId to support and we can find the request.