`onMount` not called / Component not rendered?

export default function About() {
  const [version, setVersion] = createSignal("Loading...");

  onMount(() => {
    console.log("onMount triggered");

    const version = getVersion();
    setVersion(version);
  });

  return (
    <main>
      <Title>About MCS</Title>
      <p>Running {version()}</p>
    </main>
  );
}

function getVersion() {
  return "dummy";
}