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.
return (
        <Suspense fallback={<Text text="Loading..." />}>
          <Text text="Hi!" />
          <Suspense
            fallback={<Text text={'Loading ' + page + '...'} />}
            unstable_avoidThisFallback={true}>
            <AsyncText text={page} ms={3000} />
          </Suspense>
        </Suspense>
      );
    }
    
    ReactNoop.render(<App page="A" />);
    expect(Scheduler).toFlushAndYield(['Hi!', 'Suspend! [A]', 'Loading...']);
    Scheduler.unstable_advanceTime(3000);
    await advanceTimers(3000);
    expect(Scheduler).toHaveYielded(['Promise resolved [A]']);
    expect(Scheduler).toFlushAndYield(['Hi!', 'A']);
    expect(ReactNoop.getChildren()).toEqual([span('Hi!'), span('A')]);
    
    React.unstable_withSuspenseConfig(
      () => ReactNoop.render(<App page="B" />),
      {timeoutMs: 2000},
    );
    expect(Scheduler).toFlushAndYield(['Hi!', 'Suspend! [B]', 'Loading B...']);