Shader Variants are being stripped if build them not together with scene

Case1: build scene in single asset bundle.
Result: all is fine, asset bundle 11 MB

Case2: build scene in 1 bundle, and shaders(+svc tracked from the scene) in another.
Result: 2 bundles together are 8 MB. On scene loading we can see artefacts.

How to prevent such result? Is that Unity bug?

 

Sorry, my fault. I've missed svc in my shader bundle. It prevents stripping fine