Gradio stream chatbot not working on AWS ECS

Hi, I am running a gradio inside a fastapi instance, all containerized in docker.
In local, everything works perfectly.

However, on ECS: the code breaks when calling the function bot:

def create_block(base_url):    

    def user(user_message, history):
        if user_message == '':
            user_message = 'Introduce yourself'
        return "", [['a', 'b']]                                     #up to here it works
        # return "", history + [[user_message, None]]

    def bot(history, consultant_name):                              ###NOT WORKING
        yield [['v1', 'v2']]                                        #on ECS, it keeps returning [['a', 'b']], and this function is ignored

    with gr.Blocks() as block:
        base_url = gr.Variable(value=base_url)
        consultant_name = gr.Variable(value='abc')
        chatbot = gr.Chatbot()
        msg = gr.Textbox()
        msg.submit(user, [msg, chatbot], [msg, chatbot], queue=False).then(bot, [chatbot, consultant_name], chatbot)
        # None, None, chatbot, queue=False)

    return block.queue()

app = gr.mount_gradio_app(app, create_block(base_url=base_url), path="/") 

if __name__ == "__main__":, host="", port=5000) #ssl_keyfile=ssl_keyfile, ssl_certfile=ssl_certfile

Does ECS have problem with queue(), perhaps? That is the only thing I can be thinking of
Thank you