Fluctuation in screen brightness

[Rayban7]

At night in bed I turn the brightness level down all the way. I notice when scrolling through the start menu/screen it consistently fluctuates the screen brightness when I'm at different parts of the menu.
Is this a known issue or is it my surface?
If it doesn't make sense I can try and make a quick video to demonstrate.

 

[Dos101]

Is it set to automatically adjust the screen brightness? (Charms bar -> Settings -> Change PC settings -> PC and devices -> Power and sleep)

 

[Rayban7]

Auto screen brightness, on or off, doesn't affect it at all. It seems to stop with the brightness about half way.