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**Do you want to request a *feature* or report a *bug*?**
bug, I believe, unless I misunderstand how it works
**What is the current behavior?**
Given a `Suspense` inside `Suspense` case like
```
<Suspense fallback="Fallback 1">
  <LazyText1 text="First text" />
  <Suspense fallback="Fallback 2">
    <LazyText2 text="Second text!" />
  </Suspense>
</Suspense>
```

Promises in `LazyTexts` start resolving at the same time, but if `LazyText2` is resolved first it never renders, `Fallback 2` stays.

Result:
```
First text

Fallback 2
```

Please see https://codesandbox.io/s/234o4zry7n

**What is the expected behavior?**

Every `LazyText` displayed in the end
```
First text

Second text!
```

**Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React?**
react, react-dom 16.6.0

}
      const root = ReactTestRenderer.create(<App />, {
        unstable_isConcurrent: true,
      });
      
      expect(root).toFlushAndYield(['Suspend! [Step: 1]', 'Loading...']);
      jest.advanceTimersByTime(1000);
      expect(ReactTestRenderer).toHaveYielded(['Promise resolved [Step: 1]']);
      expect(root).toFlushAndYield(['Step: 1']);
      expect(root).toMatchRenderedOutput('Step: 1');
      
      instance.setState({step: 2});
      expect(root).toFlushAndYield(['Suspend! [Step: 2]', 'Loading...']);
      jest.advanceTimersByTime(500);
      expect(root).toMatchRenderedOutput('Loading...');
      
      instance.setState({step: 3});
      expect(root).toFlushAndYield(['Suspend! [Step: 3]']);
      expect(root).toMatchRenderedOutput('Loading...');
      jest.advanceTimersByTime(1000);
      expect(ReactTestRenderer).toHaveYielded([
        'Promise resolved [Step: 2]',
        'Promise resolved [Step: 3]',
      ]);
      expect(root).toFlushAndYield(['Step: 3']);
      expect(root).toMatchRenderedOutput('Step: 3');
    });
  });
});