Xiaomi
Turn Auto-Sync Data On or Off auf Xiaomi
MIUI enables automatic synchronization with your linked Google Account by default. Every change in contacts, calendar, photos or app data gets pushed and pulled in the background, without you opening the apps involved. This keeps everything current across devices, but it also uses mobile data and processing time whenever a change is detected.
Where to find the switch
Go to Settings ➔ Accounts & sync, then use the toggle to enable or disable Auto-sync data and confirm with OK.
Turning this off is a reasonable move if you are on a limited mobile data plan or want to squeeze more runtime out of your battery. The tradeoff is that none of your accounts update automatically anymore. New contacts, edited calendar events or fresh photos backups will not sync until you either turn the setting back on or trigger a manual sync from within the specific account or app.
If only one app is causing the drain, for example a mail client checking too often, it is often better to adjust that app's own sync interval instead of disabling sync system-wide. Turning auto-sync back on after a long pause can trigger a larger sync batch, which briefly increases data usage and battery load while everything catches up.