How to reproduce:
1. Create a new Universal 3D project
2. Add Shader Variant Collection to the Assets folder (Assets → Create → Shader Variant Collection)
3. Click on created NewShaderVariants to open its Inspector
4. In the Inspector, click on the “Add shader“ button
5. Search for any Shader from any package

Expected result: Shaders from the packages are presented
Actual result: There are no Shaders from the packages presented

Reproducible in: 2021.3.40f1, 2022.3.38f1, 6000.0.10f1

Reproduced on: Windows 10
Not reproduced on: No other environment tested