How to reproduce:
1. Create an empty project using the "Universal 2D" template
2. In the Assets folder, create a "Sprite Custom Lit Shader Graph" (Right click context menu > Create > Shader Graph > URP > Sprite Custom Lit Shader Graph)
3. Open the "New Shader Graph" That has been created
4. In the Shader Graph window, add a new "Custom Interpolator" Block Node to the "Vertex" Block
5. Create a new "Color" Node, taking care to set the color to anything other than the default color.
6. Connect the "Color" Node to the "CustomInterpolator" Block Node of the "Vertex" Block
7. Create a new separate "CustomInterpolator" Node
8. Connect the created "CustomInterpolator" Node to "Base Color" of the "Fragment" Block
9. Observe the Main Preview inside the Shader Graph window (feature might need to be re-enabled on the top right corner of the Shader Graph window)
10. In the Graph Inspector menu, select the "Graph Settings" tab and change the "Material" to "Sprite Unlit"
11. Observe the Main Preview window

Expected result: Shader’s “Sprite Custom Lit” Material mode makes the Sprite change color to the desired one.
Actual result: Sprite remains black until switched to the “Custom Unlit” or "Sprite Unlit" Material mode.

Reproducible in: 2021.3.47f1, 2022.3.56f1, 6000.0.34f1, 6000.1.0b2

Reproducible on: Windows 10, Windows 11
Not Reproducible on: No other environments tested