Why does it happen? All faces are indoors, but they have really different colors from one module to other. And it doesn’t matter from which angle you look or how far away you stand. I don’t much about shaders and rendering, so I would like to be pointed what should I research to fix this or to hear some explanation or solution.
It is basically default HDRP project on Unity 2019.3 and the material is HDRP/Lit with some color inside Base Map. And the modules can be just cubes
Ok, after creating new HDRP project, clicking and googling a lot of stuff I found that issue is related to Light Probes setting in Mesh Renderer, disabling it helped to remove the color difference.
After some more research I understood that there are some light probes somewhere in the scene, but there were none. Those probes were baked into lightmap in the scene by default when you create new project and auto generate lighting is set to off so it was never regenerated or cleared. I just clicked on bake button and now those light probes are gone and cubes no longer have weird shading. It was really confusing.