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.
increment = () => {
          this.props.increment();
        };
        render() {
          return <Text text="Increment" />;
        }
      }
      function Counter({incrementBy}) {
        const [count, updateCount] = useState(0);
        const increment = useCallback(() => updateCount(c => c + incrementBy), [
          incrementBy,
        ]);
        return (
          <>
            <IncrementButton increment={increment} ref={button} />
            <Text text={'Count: ' + count} />
          </>
        );
      }
      const button = React.createRef(null);
      ReactNoop.render(<Counter incrementBy={1} />);
      expect(Scheduler).toFlushAndYield(['Increment', 'Count: 0']);
      expect(ReactNoop.getChildren()).toEqual([
        span('Increment'),
        span('Count: 0'),
      ]);
      act(button.current.increment);
      expect(Scheduler).toHaveYielded([