Have you ever experienced the contrast/brightness of the screen in Windows 10 change dynamically between applications? Especially switching from high white contrast apps like a web browser to a dark contrast application like VS Code for example? It’s pretty annoying. I have a Surface Pro 6 and its fairly off putting. 

It’s different to this setting where it changes the brightness/contrast across the board to the OS level regardless of specific apps:

The setting I am talking about where it changes contrast as you change and flick between apps.

Solution: From here https://www.windowscentral.com/how-disable-adapative-contrast-surface 

Adaptive contrast is very different than auto-brightness (or adaptive brightness) found under Settings > System > Display, which ramps up and down the display backlight on ambient lighting conditions.

Adaptive contrast differs because it adjusts based on the current image on your display rather than the ambient light in your room. It’s like edge-lit local dimming of specific zones due to what is on the screen. (This is also different than High Dynamic Range (HDR), which is much more sophisticated and precise with more color-depth).

The below is how it’s done: