Tessellation snow shader does not weld newly created verts, leaving new gaps in the mesh.

[Iconoclass]

I noticed the error on the cylinder, but not the capsule or a probuilder mesh with 90 degree edges but no curvature.

To Reproduce

1. Use a mesh that has an edge with an angle of at least 90 degrees and some curvature (cylinder).
2. Create a material with Tessellation snow shader.
3. Enable Tessellation setting (steps 2 or above).
4. Observe gaps in mesh.

Expected behavior
That newly created verts are welded when there were not previously gaps in that edge on the mesh.

Screenshot

Environment:

• OS: [e.g. Windows]
• Unity Version: [e.g. 2021.3.22f1]
• Shaders Version: [e.g. 7.2.0-dev.1]
• Rendering Pipeline: [e.g. Built-In/URP]

Additional context
These snow shaders are in development.

[orels1]

I'm not sure this is possible, as there an actual split in the normals, so there is nothing to interpolate 🤔

Disabling Phong Tessellation should solve the issue though