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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

null,
          root,
          workInProgress,
          sourceFiber,
          pingTime,
        );
        if (enableSchedulerTracing) {
          onResolveOrReject = Schedule_tracing_wrap(onResolveOrReject);
        }
        thenable.then(onResolveOrReject, onResolveOrReject);
        
        
        
        
        
        
        
        
        if ((workInProgress.mode & ConcurrentMode) === NoEffect) {
          workInProgress.effectTag |= CallbackEffect;
          
          const nextChildren = null;
          reconcileChildren(
            sourceFiber.alternate,
            sourceFiber,
            nextChildren,
            renderExpirationTime,
          );
          sourceFiber.effectTag &= ~Incomplete;