[UE 5.7] Character Hierarchy Inversion/Corruption upon Editor Duplication (Alt+Drag & Copy/Paste)

Development Programming & Scripting
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Hello everyone,

I am encountering a persistent and weird bug in the official release of Unreal Engine 5.7. I am trying to debug a friend’s project, and we are facing an issue where the component hierarchy seems to “invert” or break during actor duplication in the editor viewport.

Here is the detailed context:

1. The Setup:

  • Class: Blueprint inheriting from standard ACharacter.

  • Hierarchy:

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  • Settings: SpringArm is set to Relative transform. Use Pawn Control Rotation is ON (toggling it off doesn’t fix the issue).

2. The Bug: The issue occurs when duplicating the actor in the Level Viewport (via Alt+Drag OR Ctrl+C / Ctrl+V). It is not 100% consistent but happens very frequently.

  • Symptoms: Upon duplication, the engine treats the Camera Component as if it were the Actor’s Root.

  • Visuals: The Camera snaps to the Actor’s actual World Origin. The rest of the components (Mesh, SpringArm) move as if they are children of the Camera.

  • Gizmo Behavior: During the translation, the Gizmo appears at the Camera’s origin (visually), but the coordinates shown in the Details Panel are the correct World Coordinates of the actual Actor Root.

  • Resolution: When I deselect/reselect the actor, the bug dosn’t happen anymore with that particular actor.

It essentially feels like a serialization/initialization race condition where the deepest child (Camera) becomes the Root and the hierarchy gets flipped.

3. Troubleshooting Attempts (All Failed): I have already ruled out the following common issues:

  • Selection Error: Confirmed I am selecting the Actor Root, not a component.

  • Construction Script: Disabled Run Construction Script on Drag. The bug persists.

  • Instance Editable Variables: Confirmed that no Component variables are set to Instance Editable (which I read often breaks attachment serialization).

  • Camera Lag: Disabled Camera Lag on the SpringArm.

  • Reparenting: Tried reparenting the BP to Actor and back to Character to clear compilation cache.

  • Root Replacement: Attempted to replace the Capsule Root with a Scene Component (blocked as the Root is inherited from Character).

  • Drag Logic: The issue is strictly related to Duplication (Alt+Drag/Copy-Paste). Standard Drag (Move) works fine.

Has anyone experienced this specific “Hierarchy Inversion” in UE 5.7 or in other versions?

Any help or workaround would be greatly appreciated!