Xiaomi
Auto-download Updates via Mobile Data auf Xiaomi
MIUI checks for system updates in the background and starts downloading automatically once one is available. By default this only happens over Wi-Fi, but a dedicated setting lets you allow mobile data as well.
This matters if you have a limited data plan or roam often, since a full update package can be several hundred megabytes. Leaving mobile data enabled for updates means a download can start without you noticing, right when you switch off Wi-Fi.
The toggle sits inside the update settings, not in the general network menu, which is why many users overlook it. Once disabled, MIUI queues the update and waits for a Wi-Fi connection before downloading, but it still notifies you that an update is ready.
Where to find the setting
Go to Tap on Settings ➔ Tap on About phone ➔ Tap on MIUI version ➔ Open the Menu ➔ Tap on Update settings ➔ Enable or disable Download using mobile data.
If you travel frequently and rely on Wi-Fi hotspots, keeping this off avoids surprise data charges. If you need updates immediately regardless of network, turning it on speeds up the process but consumes your data plan.