Asset duplication occurs because non-addressable Scenes are built into the player’s local data and include all dependencies physically within the Scene data block. When the Addressables system later loads the same asset, a second instance is created in memory, resulting in duplication.

To resolve this duplication:

1. Open the Addressables Groups window via Window > Asset Management > Addressables > Groups.
2. Locate your Scene asset in the Project window.
3. Drag the Scene asset into an Addressable Group or check the Addressable checkbox in the Inspector.
4. Rebuild the Addressables content via Build > New Build > Default Build Script.

Additional Tips

• Use the Addressables Analyze tool to detect duplication issues.
• Always load these Scenes using Addressables.LoadSceneAsync instead of SceneManager.LoadScene to prevent duplication.
• If a Scene must remain non-addressable, move shared assets into a Resources folder, though this rarely stops duplication with Addressables.