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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

} while (effect !== null);
  isRendering = previousIsRendering;
  // Check if work was scheduled by one of the effects
  const rootExpirationTime = root.expirationTime;
  if (rootExpirationTime !== NoWork) {
    requestWork(root, rootExpirationTime);
  }
}
function isAlreadyFailedLegacyErrorBoundary(instance: mixed): boolean {
  return (
    legacyErrorBoundariesThatAlreadyFailed !== null &&
    legacyErrorBoundariesThatAlreadyFailed.has(instance)
  );
}
function markLegacyErrorBoundaryAsFailed(instance: mixed) {
  if (legacyErrorBoundariesThatAlreadyFailed === null) {
    legacyErrorBoundariesThatAlreadyFailed = new Set([instance]);
  } else {
    legacyErrorBoundariesThatAlreadyFailed.add(instance);
  }
}
function flushPassiveEffects() {
  if (passiveEffectCallback !== null) {
    Schedule_cancelCallback(passiveEffectCallbackHandle);
    
    
    passiveEffectCallback();
  }
}
function commitRoot(root: FiberRoot, finishedWork: Fiber): void {