When App Lock stops working on your vivo S50, your private apps may open without asking for a password or fingerprint. That defeats the whole point of using the feature and can feel unsettling. The issue is usually caused by permission limits, background restrictions, or a small setting that changed without you noticing.
Why App Lock Is Not Working on Your vivo S50
- App Lock permissions are disabled or restricted.
- The app was excluded from background activity.
- Fingerprint or face data is not syncing properly.
- Battery optimization is limiting App Lock behavior.
- A temporary system glitch is preventing the lock from triggering.
1. Make Sure App Lock Is Enabled
App Lock must be actively turned on for each app you want to protect. If it gets disabled, locked apps will open normally without any security prompt.
Open Settings, and then tap Security.
Tap App Lock, and make sure the feature is turned on.
Select the apps you want to protect and confirm they are toggled on.
2. Recheck Your Unlock Method
If your fingerprint or face data fails to load properly, App Lock may silently stop working. Refreshing the unlock method helps restore normal behavior.
Open Settings, and then tap Security.
Tap Fingerprint or Face recognition, and verify your data is still registered.
Test the unlock method to confirm it responds correctly.
3. Allow App Lock to Run in the Background
App Lock needs background access to trigger the lock screen each time you open an app. If background activity is restricted, the feature may not activate at all.
Open Settings, and then tap Battery.
Tap Background app management, and find App Lock.
Set it to allow background activity so it can work continuously.
4. Disable Battery Optimization for App Lock
Battery optimization can stop App Lock from running when the phone tries to save power. This is a common reason why the lock works sometimes and fails at other times.
Open Settings, and then tap Battery.
Tap Battery optimization, and locate App Lock.
Set it to Not optimized to prevent restrictions.
5. Restart Your Phone
Temporary system issues can interfere with security services. Restarting the phone refreshes system processes and often restores App Lock immediately.
Swipe down from the top of the screen to open Quick Settings.
Tap the Power icon, and then tap Restart.
Wait for the phone to fully boot, then test App Lock again.
6. Turn App Lock Off and On Again
Toggling the feature refreshes its internal settings. This helps when App Lock is enabled but not responding.
Open Settings, and then tap Security.
Tap App Lock, and turn it off temporarily.
Turn it back on and reselect your locked apps.
Once App Lock is working properly again, your apps should immediately ask for authentication before opening. After adjusting permissions and removing restrictions, the feature becomes reliable and consistent on the vivo S50.
FAQs
Why does App Lock work only after restarting my vivo S50?
This usually means the feature is being restricted in the background. Allowing background activity and disabling battery optimization prevents it from stopping after restarts.
Does App Lock fail after a system update on vivo phones?
Yes, some updates reset permissions or battery rules. Rechecking App Lock settings after an update often fixes the issue.
Can third party cleaner apps break App Lock?
Yes. Task killers and battery saver apps can stop App Lock services. Removing or limiting those apps helps App Lock function normally again.
