FWorldPartitionActorDesc::Unloaded and FWorldPartitionActorDesc::IsLoaded does not work!

I need check if a WorldPartitionActorDesc is loaded.
But FWorldPartitionActorDesc::IsLoaded always return true even right after I unloaded the FWorldPartitionActorDesc.
For example:

FWorldPartitionReference HLODActorRef = HLODActorHandle.ToReference();
FWorldPartitionActorDesc* HLODActorDesc = ActorDescContainer->GetActorDesc(HLODActorGuid);
HLODActorDesc->Unload();
//bIsLoaded is alweay true no matter what I do, until I unregister the the world partition loaderadapter.
bool bIsLoaded = HLODActorDesc->IsLoaded(true);
bIsLoaded = HLODActorDesc->IsLoaded();