OnePlus
Adjust screen brightness manually auf OnePlus
OnePlus phones handle screen brightness through a slider that sits in the display settings and in the quick settings panel of the status bar. Both controls point to the same value, so a change in one place shows up in the other immediately.
Adaptive Brightness watches the light sensor and nudges the slider up or down based on your surroundings. That is convenient outdoors, but it can override a level you just set manually, especially when you move between rooms with different lighting.
To set brightness by hand, go to Open the Settings ➔ Tap on Display ➔ Swipe left or right to adjust the brightness. Dragging the slider left dims the screen, dragging it right brightens it, and the change applies instantly without a confirmation step.
The same slider appears when you pull down the status bar for quick settings, which is faster if you only need a quick adjustment and do not want to open the full settings menu.
If the screen still changes brightness on its own after a manual adjustment, Adaptive Brightness is likely still switched on and correcting the level in the background. Turning that toggle off keeps your manual setting fixed until you change it again.