the langchain callback handler does not display a tree-like representation of the trace

portkey_handler = LangchainCallbackHandler(
    api_key=".....",
)

llm = ChatOpenAI(
    api_key=SecretStr("....."),
    base_url=PORTKEY_GATEWAY_URL,
    default_headers=createHeaders(
        trace_id=thread_id,
        config=".....",
        metadata={
            ....
        },
    ),
    callbacks=[portkey_handler],
)