Xiaomi
Turn Full Screen Mode On or Off for Specific Apps auf Xiaomi
Full screen mode on Xiaomi phones stretches an app's interface across the entire display, including the area behind the camera cutout and status bar. Some apps were never designed for that aspect ratio, so buttons get cut off, images distort, or black bars appear instead of a filled screen.
MIUI handles this setting per app instead of with one global switch. That is why disabling full screen mode for a single game or streaming app leaves every other app untouched.
To change it, open Settings ➔ Display ➔ Fullscreen mode. Xiaomi sorts the app list here based on how well each app supports the extended aspect ratio, but that sorting is only a suggestion. Tap the switch next to any app to enable or disable full screen manually.
If an app still looks wrong after toggling this setting, the problem often sits with the app itself rather than with MIUI. Older apps that were never updated for taller displays sometimes ignore the full screen flag completely. Check for an app update before changing the display setting again.
Turning full screen mode off for a specific app does not reduce its resolution. It only changes how the interface is scaled and where system elements like the notch or camera cutout sit relative to the content.