Automatic LOD fails, and GPU Occlusion Culling incompatibility occurs when using spline-based quad-topology meshes

How to reproduce:

1. Open the “QuadTopoBug.zip“ project
2. Open the “SampleScene“
3. Observe the Game view

Actual result: The GameObject on the left has holes
Expected result: The GameObject on the left looks identical to the one on the right

Reproducible in: 2023.3.0a19, 6000.0.66f1, 6000.3.5f1, 6000.4.0b5, 6000.5.0a5
Could not test in: 2023.3.0a2 (Resident Drawer hasn’t been introduced yet)

Reproduced on: Windows 11 Pro (25H2)
Not reproduced on: No other environment tested

Notes:

• GPU Occlusion culling must be enabled for the bug to appear
• When in Shaded Wireframe mode in Scene view, the issue does not reproduce visually; the holes can be observed by the GameObject's outline
• Reproducible with all Graphics APIs