Remove a Synced Account
When you disconnect from a service like Facebook on your Samsung phone, the app itself often stays signed in because the account is still linked in the system settings. This happens because Samsung keeps every added account - email, cloud, social media - in one central list that also controls background sync. Removing it there is the only way to stop the syncing and fully disconnect the account from the device.
Turn Auto Sync On or Off for Accounts
If your contacts, calendar entries or photos suddenly stop updating on your Samsung phone, automatic sync for that account is probably switched off. Auto sync data is the background function that keeps your Google, Samsung or other accounts current without you opening each app. Turning it off saves battery and mobile data, but new changes will only appear once you manually refresh or open the affected app.