requestAnimationFrame выдает неверную метку времени при отображении диалогового окна подтверждения (Chromium?)

const cache = {
  start: null,
  target: null,
  time: 2000
};

function animate(timestamp) {
  console.log(timestamp);
  if (cache.start === null) {
    cache.start = timestamp;
  }
  var progress = timestamp - cache.start;
  cache.target.style.left = Math.min(progress / 10, cache.time / 10) + 'px';
  if (progress < cache.time) {
    requestAnimationFrame(animate);
  } else {
    cache.target.style.left = 0;
    cache.start = null;
  }
}

const render = () => {

  requestAnimationFrame((timestamp) => {

    const performanceNow = performance.now();

    animate(performanceNow)
  });
}

(function() {
  const target = document.getElementsByTagName("div")[0];
  cache.target = target;
  const cb = document.getElementsByTagName("input")[0];


  const btn = document.getElementsByTagName("button")[0];
  btn.addEventListener("click", function() {
    if (cb.checked) {
      const confirmed = confirm("Just click 'OK' to start the animation, ok?");
      if (confirmed) {
        render();
      }
    } else {
      requestAnimationFrame(animate);
    }
  })
})();

html,
body {
  padding: 0;
  margin: 0;
}

div {
  width: 50px;
  height: 50px;
  border: 1px solid black;
  background-color: yellowgreen;
  position: absolute;
  top: 50px;
}

button {
  margin-top: 20px;
}

<button type="button">Start</button>
<label>
  <input type="checkbox" />use "confirm"</label>
<div>

</div>