Reproduction steps:
1. Open the attached “IN-134315” project
2. In the Project view, select the “dirt” Autotile asset (Assets/dirt.asset)
3. In the Inspector, make 2 tiles have the same tiling rules (with a red border to indicate conflict)
4. Use the “Load” button to override the current Tilemap with “Blank Template”
5. Interact with the Tilemap again to change the mask rules
6. Observe the Tilemap in the Inspector

Actual result: Tiles still use old rules even after overriden with new template
Expected result: Tiles lose reference to old rules once overriden with new template

Reproducible with: 6000.3.0a1, 6000.3.9f1, 6000.4.0a1, 6000.4.0b9, 6000.5.0a1, 6000.5.0a7
Couldn’t test with: 6000.0.68f1 (Couldn’t resolve package issues), 6000.1.0a2 (tilemap templates don’t work)

Reproducible on: Windows 11 (by reporter), macOS 26.2
Not reproducible on: No other environments tested