Can't the run_name when running graph

[Daniel-963]

Checked other resources

• This is a bug, not a usage question. For questions, please use GitHub Discussions.
• I added a clear and detailed title that summarizes the issue.
• I read what a minimal reproducible example is (https://stackoverflow.com/help/minimal-reproducible-example).
• I included a self-contained, minimal example that demonstrates the issue INCLUDING all the relevant imports. The code run AS IS to reproduce the issue.

Example Code

# when i def the chatbot using follow code,i cant get the name when run the workflow
async def chatbot1(state: State, config: RunnableConfig):
        config["run_name"] = "chatbot1"
        return {"messages": [await llm1.ainvoke(state["messages"], config)]}

# here i cant get name
async def message_generator(user_input: str):
    """Generate streaming messages from the graph."""
    inputs = [HumanMessage(content=user_input)]

    async for msg, metadata in graph.astream(
        {"messages": inputs}, stream_mode="messages"
    ):
        # here is none.
        # but i can get it when i using second way
        print(msg.name)
        yield json.dumps({"content": msg.content})

# but when using follow code,i can
    async def chatbot1(state: State, config: RunnableConfig):
        RunnableConfig(run_name="chatbot1")
        return {"messages": [await llm1.ainvoke(state["messages"], RunnableConfig(run_name="chatbot1"))]}

# that's why? is it a bug?

Error Message and Stack Trace (if applicable)

it's not a Error ,it's a phenomenon

Description

when i use first way to def the run_name,i cant get name in workflow processing ,but i can get it using seconds code!

System Info

pass