Unreal Engine Issues and Bug Tracker (UE-187098)

Description

Attached actors do not return to LevelInstance space at the end of LevelInstance editing, and bounds contains level instance offset location. This results in huge bounds.
My workaround is:

void FLevelUtils::ApplyEditorTransform(const ULevelStreaming* StreamingLevel, bool bDoPostEditMove, AActor* Actor)
{
	check(StreamingLevel);
	if (ULevel* LoadedLevel = StreamingLevel->GetLoadedLevel())
	{	
		FApplyLevelTransformParams TransformParams(LoadedLevel, StreamingLevel->LevelTransform);

#if 1 //workaround
		// Move parent actor instead of child actor
		USceneComponent* RootComponent = Actor->GetRootComponent();
		if (RootComponent && RootComponent->GetAttachParent())
		{
			while( RootComponent->GetAttachParent() )
			{
				RootComponent = RootComponent->GetAttachParent();
			}
			Actor = RootComponent->GetOwner();
		}
#endif
		TransformParams.Actor = Actor;
		TransformParams.bDoPostEditMove = bDoPostEditMove;
		ApplyLevelTransform(TransformParams);
	}
}

void FLevelUtils::RemoveEditorTransform(const ULevelStreaming* StreamingLevel, bool bDoPostEditMove, AActor* Actor)
{
	check(StreamingLevel);
	if (ULevel* LoadedLevel = StreamingLevel->GetLoadedLevel())
	{
		const FTransform InverseTransform = StreamingLevel->LevelTransform.Inverse();
		FApplyLevelTransformParams TransformParams(LoadedLevel, InverseTransform);
		
#if 1 //workaround
		USceneComponent* RootComponent = Actor->GetRootComponent();
		if (RootComponent && RootComponent->GetAttachParent())
		{
			while( RootComponent->GetAttachParent() )
			{
				RootComponent = RootComponent->GetAttachParent();
			}
			Actor = RootComponent->GetOwner();
		}
#endif

		TransformParams.Actor = Actor;
		TransformParams.bDoPostEditMove = bDoPostEditMove;
		ApplyLevelTransform(TransformParams);
	}
}

Steps to Reproduce

Create a LevelInstance with some actors
Places the levelinstance away from 0,0,0
(optional) set WorldPartition Cell Size And Loading Range low value in WorldSetting Pane
Select the levelinstance in the outliner and press edit button in detail panel
Select an actor in the outliner and attach it to another actor
Commit the level instance
Start PIE and move away far until actor streams out

[Link Removed]is the repro project.

Result:

The actor cluster promoted to a higher grid level than expected, significantly increasing stream out distance.

You can also see promoted actors in StremingGeneration log (Saved\WorldPartition*.log)

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Fixed

Component	UE - World Creation - Worldbuilding Tools - Level Instances
Affects Versions	5.1, 5.2
Target Fix	5.4

Fix Commit	26094801
Main Commit	26095012

Created	May 26, 2023
Resolved	Jun 19, 2023
Updated	Jun 22, 2023

UE-187098

Actor attached to other actor in LevelInstance has very large bounds

Actor attached to other actor in LevelInstance has very large bounds

Result:

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