I have request that takes some time and I want to send status updates to the user while it's running. The request is successful, but the status isn't being streamed. The code I have works in development, but not when deployed to Vercel. It seems like 'res.write()' isnt working properly. I've found solutions for the app router, but I'm using the pages router. Anyone know what could be causing it and a fix?

async function status(res, name, callback) {
  console.time(name);
  try {
    const msg = { status: `${name}` };
    res.write(JSON.stringify(msg));
    return await callback();
  }
  catch (err) {
    console.log(`Error at: ${name}`);
    throw err;
  }
  finally {
    console.timeEnd(name);
  }
}

async function requestStatus(method, path, body, setStatus) {
  const response = await fetch(`${process.env.NEXT_PUBLIC_API_URL}/${path}`, {
    method: method,
    headers: {
      'Content-Type': 'application/json',
    },
    body: JSON.stringify(body),
  });
  console.log('response', response)
  if (!response.ok) {
    throw new Error('Network response was not ok');
  }

  const reader = response.body.getReader();
  const decoder = new TextDecoder();
  let data = null

  while (true) {
    const { done, value } = await reader.read();
    console.log({ done, value })
    if (done) {
      break
    };
    const msg = JSON.parse(decoder.decode(value));
    console.log('msg', msg)
    if (msg.error) {
      throw new Error(msg.message)
    }
    if (msg.success) break
    data = msg
    setStatus(msg.status)
  }
  return data
}