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 [count, updateCount] = useState('(empty)');
        useEffect(() => {
          Scheduler.unstable_yieldValue(`Schedule update [${props.count}]`);
          updateCount(props.count);
        }, [props.count]);
        return <Text text={'Count: ' + count} />;
      }
      act(() => {
        ReactNoop.render(<Counter count={0} />, () =>
          Scheduler.unstable_yieldValue('Sync effect'),
        );
        expect(Scheduler).toFlushAndYieldThrough([
          'Count: (empty)',
          'Sync effect',
        ]);
        expect(ReactNoop.getChildren()).toEqual([span('Count: (empty)')]);
        ReactNoop.flushPassiveEffects();
        expect(Scheduler).toHaveYielded(['Schedule update [0]']);
        expect(Scheduler).toFlushAndYield(['Count: 0']);
      });
      act(() => {
        ReactNoop.render(<Counter count={1} />, () =>
          Scheduler.unstable_yieldValue('Sync effect'),
        );
        expect(Scheduler).toFlushAndYieldThrough(['Count: 0', 'Sync effect']);
        expect(ReactNoop.getChildren()).toEqual([span('Count: 0')]);
        ReactNoop.flushPassiveEffects();