Almost invisible grid on photo in editing screen in Lightroom

[Marcus5DD6]

I have a small problem, thats quite easy to see on some darker photos in Lightroom classic. There is a grid of small squares, (appox 1cm) almost invisible. These dissapear when I zoom into the photo or full screen the photo.

I will upload two photos, one with the squares and one zoomed in. Hopefully you can see the difference. 

I asume this is either a simple resolution setting or I need a higher resoution monitor.

Thanks in advance for and help.

[Jim Wilde]

To be honest, I can't see the grid lines that you refer to (though I accept that you can). I wonder if it's the same issue as in this post: https://community.adobe.com/t5/lightroom-classic-discussions/grid-lines-show-in-picture/m-p/13478335...

[Marcus5DD6]

Granted its not easy to see the squares. If you zoom right in on the first photo its quite blurry and u might make out the squares.

[Keith Reeder]

Which camera is this?

[Marcus5DD6]

Nikon D850

[Keith Reeder]

Thanks - just wondered whether it was a camera with a known problem in this regard.

I have to say that I'm with Jim - I've downloaded the first file, viewed it (not in Lr) at 1000%, cranked brightness/contrast etc. right up, and I can't see the grids either.

[Marcus5DD6]

Can you see them in the above photo? I can see squares about 1cm in size, and are almost the same colour as the photo itself. 

I have though maybe its a monitor issue, but it doesnt make sence for full screen to be perfect quility.