How do i connect my xbox one s to my tv to still get 4k picture but at the same time...

I don’t have a xbox one s or x. Just a normal xbox one. I do realize that i wont be able to have full 4K graphics when using just the standard console. But what i don’t understand is how my old led tv has better picture quality with my games than my 4K
tv.

My TV doesn't support HDR at all but it is 4k capable. I have tried having the XBOX One S directly connected to the TV and through the receiver with no luck getting anything 4k out of the One S.

I don't think so, Robin. I had an LG OLED 4K TV. And the Xbox One S was connected to to the LG TV and I used to play 4K games. Even if that's the case to play only 4K Blu Rays, it's still not supporting.

The Xbox One S plays games at 1080p but if played on a 4K screen, it upscales it to 4K,

The One X is needed for true native 4K,

I upgraded my Xbox One to the One S at launch to get full use out the 4K media content,

Then i upgraded my One S to the One X at launch to play games and media at true 4K,

seeing that you've already tried what i would have suggested, I'm not sure of what else you can try.

I have a 4k samsung smart tv hdr this is the model: UN40NU7100FXZA; and I have the Fat Xbox One not S. So the image looks pixelated, poor quality image, I have used the "Game Mode" option and still look bad. On my previous Philips 32" led tv FHD
everything looks perfect and no configuration was needed. What do I have to configure?

If I'm not mistaking a Xbox One will only go up to 720p and Xbox One S and X will do 4k. I'm not sure how to configure your TV, however yourself can go to the picture settings on your TV and change them to your likings.

I did have it set up that way but in the xbox audio settings it wouldnt let me change the settings to Dolby Atmos. It just said the xbox doesnt support these settings.