I am trying to load a level without blocking the entire scene. I am using the functionality highlighted in this post : Package Async Load VS OpenLevel VS Travel - UE4 AnswerHub .
So I first cache the level with LoadPackageAsync(), store the package and world as UProperties, then call UGameplayStatics::OpenLevel. Which seems to be working, except none of the sublevels (using world composition) are being loaded.
For debugging purposes I am printing out all streaming levels in the BeginPlay() of my game mode with GetWorld()->StreamingLevels. When starting the level in PIE all the levels are there, when loading asynchronously the list is empty.
Any idea what I might be missing? Maybe a dev?