SSE-cleanup not working in solid start

chat.tsx

import { createEffect, createSignal, onCleanup } from 'solid-js'
import server$, { eventStream } from 'solid-start/server'

function createEventStream({ url }: { url: string }, onMessage: (ev: MessageEvent) => void) {
  createEffect(() => {
    const eventSource = new EventSource(url)

    eventSource.addEventListener('chat', (event) => {
      onMessage(event)
    })

    onCleanup(() => eventSource.close())
  })
}

export default function Page() {
  let [state, setState] = createSignal('test data')
  createEventStream(
    server$(async function () {
      return eventStream(server$.request, (send) => {
        send('chat', 'Hello world')
        let x = 1
        const interval = setInterval(() => {
          send('chat', 'Hi :-D ' + x++)
          console.log(x)
        }, 2000)
        return () => {
          console.log('disconnect')
          clearInterval(interval)
        }
      })
    }),
    (event) => {
      setState(event.data)
    },
  )

  return <h1 id="chat">{state()}</h1>
}