Unexpected behavior with async produce context

[echo8]

I'm using this client's producer in an HTTP service but am running into some unexpected behavior regarding context usage.

Here is a simple example:

func httpHandler(w http.ResponseWriter, r *http.Request) {
	record := &kgo.Record{
		// ...
		Context: context.Background(),
	}
	client.Produce(r.Context(), record, producePromise)
	w.WriteHeader(http.StatusNoContent)
}

func producePromise(r *kgo.Record, err error) {
	if err != nil {
		log.Println("Produce failed.", err)
	} else {
		log.Println("Produce succeeded.")
	}
}

When I call this HTTP endpoint Produce failed. context canceled is logged. So it seems that the canceling of the request's context is causing the buffered record to also be canceled. This is unexpected to me because the record's context is being set to a totally different (background) context. In this case shouldn't the request's context only be used until the record is buffered?