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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

expect(onInteractionTraced).toHaveBeenCalledTimes(2);
              expect(onInteractionTraced).toHaveBeenLastNotifiedOfInteraction(
                interactionHighPri,
              );
              expect(
                onInteractionScheduledWorkCompleted,
              ).not.toHaveBeenCalled();
              expect(getWorkForReactThreads(onWorkStarted)).toHaveLength(1);
              expect(getWorkForReactThreads(onWorkStopped)).toHaveLength(0);
            },
          );
        });
        expect(ReactTestRenderer).toHaveYielded(['SecondComponent']);
        expect(onInteractionTraced).toHaveBeenCalledTimes(2);
        expect(onInteractionScheduledWorkCompleted).toHaveBeenCalledTimes(1);
        expect(
          onInteractionScheduledWorkCompleted,
        ).toHaveBeenLastNotifiedOfInteraction(interactionHighPri);
        
        expect(onRender).toHaveBeenCalledTimes(1);
        let call = onRender.mock.calls[0];
        expect(call[0]).toEqual('test');
        expect(call[5]).toEqual(mockNow());
        expect(call[6]).toMatchInteractions(
          ReactFeatureFlags.enableSchedulerTracing
            ? [interactionLowPri, interactionHighPri]
            : [],
        );
        onRender.mockClear();
        advanceTimeBy(100);