I took a quick look at your files, and both scenes have very different light settings and arrangements.
One scene has Sunlight, dome light, and some extra interior lights; the other scene only has interior lights.
None of them are wrong, really just different approaches, and they should look different.
Now, in my opinion, I follow real-world rules. For example, if your room has windows, then I test using Sunlight, depending on the moth you are trying to achieve. After that, I place lights inside, just like it would be in a real room. Most of the time, that would be enough. But if things are not looking the way you need, then you can start adding 'fill lights', to accentuate some objects or areas. Think of the extra lights a Photographer would use.
If your room doesn't have windows then I only will use the interior lights and then some accent lights.
Having said all that, I also build my scene just like the real-world room will be, I don't use single planes for ceiling or floor. and I don't hide walls or make them semi transparent. There is a camera clipping feature on 3D Max camera, that you can use instead of transparent walls. Also, there is a VRay clipper if you need more control.
Last but not least. I would recommend to just forgetting about all the jumps and hoops you read online about V Ray settings, most of those are already outdated settings. Today's V Ray is very straightforward, you use default settings, increase your render noise threshold to render faster, or reduce it values to render and cleaner image.
You can activate the denoiser which will really help you with render times. Brute force method and Light cashe will render very high-quality images with very little effort. You could use Irradiance as the first bounce, but then you need to start dig up for settings, that by the time you achieve what you want, Brute force already has it rendered 😛
If I have time I can set up a scene for you to review what I talked about, but no promises. lately, I been very overwhelmed with projects.
But I would recommend resetting your V Ray settings, (Switch your render engine to Scanline then switch back to V Ray) then, deleting all lights, and just placing the one that there should be, maybe a sun, if there is a window, then a light inside the kitchen, maybe is a series of IES lights or a single 2x4 fluorescent light, then a light under the microwave as an accent light, and a light simulating light coming from the upper floor. And see how that goes. Don't forget so adjust the camera exposure as need it.
Best luck.
