Reproduction steps:
1. Open the attached “repro_IN-91640“ project
2. Open the “Assets/Scenes/SampleScene.unity“ Scene
3. Select the “Assets/CompilationTest.shadergraph“ Shader
4. In the Inspector, press “View Generated Shader“
5. In the opened “GeneratedFromGraph-CompilationTest.shader“, search for “struct VertexDescription“
6. Once found, notice what it consists of

Expected result: “VertexDescription” method consists of three “half3” values
Actual result: “VertexDescription” method consists of two “half3” and one “float3” value

Reproducible with: 2021.3.47f1, 2022.3.55f1, 6000.0.33f1, 6000.1.0b1

Reproducible on: Windows 10 (22H2), Windows 11 (23H2)
Not reproducible on: No other environments tested