OnePlus
Enable or Disable Auto-Sync for Personal Data auf OnePlus
Auto-sync personal data controls whether your OnePlus phone pulls in changes made to your synced accounts, such as a new contact added in Google Contacts online or a calendar entry edited on another device. With the option off, the phone stops checking for those updates in the background, so you only see current data after a manual sync or app refresh.
Turning sync off can help save battery and mobile data, especially with several accounts connected at once. It also matters for privacy, since disabling it stops apps from silently uploading local changes to a linked cloud account. The trade-off is that documents, settings and app data fall out of date until you sync again.
To change the setting, open Settings ➔ Accounts, then use the switch to enable or disable Auto-sync personal data and confirm with OK.
If only one account causes trouble, for example duplicate calendar entries from a work profile, turn off sync for that single account instead of switching off the setting for everything. The rest of your accounts keep updating as normal.