https://codesandbox.io/s/upbeat-frost-3tt25

1. Press Suspend, see "Loading..."
2. Wait five seconds, you'll see "Happy birthday" at some point 
3. You won't see it again no matter how long you wait

Expected: you'll see it every five seconds.
await C.resolve();
    ReactNoop.render(<Foo step={1} />);
    expect(Scheduler).toFlushAndYield([
      'C',
      'Suspend! [D]',
      'Loading D',
      'Loading C',
      'Loading D',
    ]);
    expect(ReactNoop).toMatchRenderedOutput(
      <>
        <span>Loading C</span>
        <span>Loading D</span>
      </>,
    );
    await D.resolve();
    expect(Scheduler).toFlushAndYield(['C', 'D']);
    expect(ReactNoop).toMatchRenderedOutput(
      <>
        <span>C</span>
        <span>D</span>
      </>,
    );
  });
  it('avoided boundaries can be coordinate with SuspenseList', async () => {
    let A = createAsyncText('A');
    let B = createAsyncText('B');
    let C = createAsyncText('C');
    function Foo({showMore}) {