Sandbox: https://codesandbox.io/s/cranky-kapitsa-op3jh

Repro: type "a" and then after a second "b"

Expected: Eventually you'll see "ab" in all fields. Pending "..." indicator goes away.

Actual: You'll keep seeing "a" in low pri field. Pending "..." indicator is stuck.
const [counter, _setCounter] = useState(1);
      setCounter = _setCounter;
      return <Component count={counter} />;
    }
    function Component({count}) {
      const [state, dispatch] = useReducer(() => {
        
        
        
        Scheduler.unstable_yieldValue('Reducer: ' + count);
        return count;
      }, -1);
      useEffect(() => {
        Scheduler.unstable_yieldValue('Effect: ' + count);
        dispatch();
      }, [count]);
      Scheduler.unstable_yieldValue('Render: ' + state);
      return count;