Xiaomi
Turn Off Mobile Data When Device Is Locked auf Xiaomi
MIUI includes a battery feature that switches off mobile data automatically once the screen locks. The idea is simple: no active display usually means no urgent need for a live connection, so cutting data saves battery in the background.
The setting controls how long MIUI waits after locking the screen before it disables mobile data. You can pick a short delay, a longer one, or disable the automatic cutoff completely.
To adjust it, go to Settings ➔ Battery & performance ➔ Settings ➔ Turn off mobile data when device is locked. From there, choose In 5 minutes, 10 minutes, 30 minutes, or Never.
A short delay like 5 minutes is useful if battery life matters more than instant notifications. A longer delay or Never keeps messaging apps, calls, and background syncs responsive at all times, at the cost of slightly higher battery use.
This setting only affects mobile data over cellular networks. It has no effect on Wi-Fi connections, so devices that stay on Wi-Fi while locked will keep syncing regardless of this timer.
If you rely on instant delivery for chat apps, banking alerts, or call forwarding, setting this to Never avoids delayed notifications. If battery runtime is the priority and you check your phone frequently anyway, a shorter delay works better.