Xiaomi
Turn On/Off Auto Brightness auf Xiaomi
Auto Brightness on Xiaomi phones uses the light sensor near the front camera to measure ambient light and adjust the screen automatically. This is meant to keep text readable indoors and outdoors without you constantly touching the brightness bar.
The function does not lock the brightness slider. Even with Auto Brightness enabled, you can still drag the slider up or down. The system treats your manual adjustment as a temporary offset and keeps learning from it, which is why the screen sometimes jumps back to a different level shortly after you change it yourself.
To turn the function on or off, go to Tap on Settings ➔ Tap on Display ➔ Tap on Brightness level ➔ Enable or disable Automatic brightness.
Disable Auto Brightness if you want a fixed brightness level regardless of lighting, for example when reading in bed at night or working under constant indoor light. Keep it enabled if you move between indoor and outdoor environments often, since it reduces eye strain and saves battery in bright conditions.
If the screen still feels too dark or too bright after adjusting this setting, check for dirt or a screen protector covering the light sensor, since that can throw off the readings.