Vertex colors are being stripped after build

First of all, my meshes have assigned vertex colors from external software, and the only t$$anonymous$$ng that doesn't work is loading vertex colors. Vertices and everyt$$anonymous$$ng load correctly.

I am loading my mesh using "Resources.Load". It works in editor, but after build "mesh.GetColors" returns empty list of colors.

Is unity stripping my vertex colors? How can I prevent it?

*Happens both in il2cpp and mono build