Level streaming issue

Hello everyone. I had a very annoying problem with UGameplayStatics::UnloadStreamLevel function.

  1. I have an TArray with Streaming Levels Names. All of them are correct.
  2. Then I try to unload them one by one. I start UnloadStreamLevel only when previous unloaded level called OnLevelUnloaded delegate.
  3. As a result UE4 unloads only first level in the Array. All other stay loaded.
  4. If I add the delay node into the child blueprint before next UnloadStreamLevel attempt, UE4 successfully unload levels from the list.
    Thank you for any help!