Reproduction steps:
1. Open the “ReproProject“ project
2. Create a new Material (Assets > Create > Material)
3. Select the “Assets/New Material“
4. Change Shader to the “ShadowReceiverAdditional“ Shader in the Inspector window
5. Observe the Inspector window

Expected result: The Surface Type is set to “Transparent”
Actual result: The Surface Type is “Opaque“

Reproducible with: 2021.3.36f1, 2022.3.24f1, 2023.2.18f1, 6000.0.0b14

Reproducible on: Windows 11 Pro (22H2)
Not reproducible on: No other environment tested

Note:
When creating a new Material by right clicking the “Assets/ShadowReceiverAdditional“ ShaderGraph (Create > Material), this issue does not reproduce, and the Surface Type is set to “Transparent“ as expected