What to do if Galaxy S9 Plus still unlocks by swiping even if Fingerprint lock and Iris scan are enabled

One interesting issue on the #GalaxyS8 and #GalaxyS9 devices we’re trying to investigate at this time is about the loss of ability of Fingerprint scan and Iris scan features to lock the screen. We are yet in the process of gathering information if the problem is affecting many users right now so keep yourself updated by following this page. If you know of similar cases, feel free to contact us so we can update our community as well.

Today’s problem: Galaxy S9 Plus unlocks by swiping even if Fingerprint lock and Iris scan are enabled

Hello. I’ve just got a Galaxy S9 Plus, and even though I have set Fingerprint Unlock, and Iris Scan, the screen unlocks just by swiping. I have done a Hard Reset on the phone, and I have also checked the Smart Lock settings (they are all off) but it just won’t lock properly. The fingerprint reader DOES work, since I have used it with Samsung Pass. Do you know what could I do?

Solution: We’ve seen some Galaxy S8, S8 Plus, S9, and S9 Plus users having PIN and other security locks issues over the past few days so this may be firmware or Samsung-related problem. We’re currently investigating the problem so we have no idea how many are affected by this bug. There’s no official from Samsung so far so all you have to do is to stick to tried and tested basic software solutions like wiping the cache partition, booting to safe mode, resetting all settings, and factory reset.

Solution #1: Clear the cache partition

If the problem started after installing an update for Android Oreo, we suggest that you clear the cache partition first. This will ensure that you refresh the system cache. Here’s how to do it:

1. Turn off the device.
2. Press and hold the Volume Up key and the Bixby key, then press and hold the Power key.
3. When the Android logo displays, release all three keys.
4. An ‘Installing system update’ message will show for 30 – 60 seconds before the Android system recovery menu options appear.
5. Press the Volume down key several times to highlight wipe cache partition.
6. Press Power key to select.
7. Press the Volume down key to highlight yes, them and press the Power key to select.
8. When the wipe cache partition is complete, Reboot system now is highlighted.
9. Press the Power key to restart the device.

Solution #2: Observe in Safe Mode

In case the problem is due to a third party app, you can also check how screen security works when the phone is on safe mode. In this mode, no third party app runs and only pre-installed ones can work. So, if security lock works normally on safe mode, that’s a confirmation that our suspicion is right.

To boot your S9 Plus to safe mode:

1. Turn the device off.
2. Press and hold the Power key past the model name screen.
3. When “SAMSUNG” appears on the screen, release the Power key.
4. Immediately after releasing the Power key, press and hold the Volume down key.
5. Continue to hold the Volume down key until the device finishes restarting.
6. Safe mode will display in the bottom left corner of the screen.
7. Release the Volume down key when you see Safe Mode.
8. Check for the problem.

Remember, safe mode is a tool, not a solution. If security lock works in this mode, you can bet one of your installed apps is to blame. To identify which of your apps is causing the trouble, you should boot the phone back to safe mode and follow these steps:

1. Boot to safe mode.
2. Check for the problem.
3. Once you’ve confirmed that a third party app is to blame, you can start uninstalling apps individually. We suggest that you begin with the most recent ones you added.
4. After you uninstall an app, restart the phone to normal mode and check for the problem.
5. If your S9 is still problematic, repeat steps 1-4.

Solution #3: Reset all settings

If nothing changes after clearing the cache partition or when your phone is on safe mode, then you ought to try clearing all software settings. Here’s how you do it:

1. From the Home screen, swipe up on an empty spot to open the Apps tray.
2. Tap General Management > Reset settings.
3. Tap Reset settings.
4. If you have set up a PIN, enter it.
5. Tap Reset settings. Once complete a confirmation window will appear.

Solution #4: Factory reset

For most Android users, factory reset is the last resort in this case. This will return all software settings to their defaults. If there’s a bug in the system, factory reset might fix it. Here’s how you do it:

1. Create a backup of your data.
2. Turn off the device.
3. Press and hold the Volume Up key and the Bixby key, then press and hold the Power key.
4. When the green Android logo displays, release all keys (‘Installing system update’ will show for about 30 – 60 seconds before showing the Android system recovery menu options).
5. Press the Volume down key several times to highlight ‘wipe data / factory reset’.
6. Press Power button to select.
7. Press the Volume down key until ‘Yes — delete all user data’ is highlighted.
8. Press Power button to select and start the master reset.
9. When the master reset is complete, ‘Reboot system now’ is highlighted.
10. Press the Power key to restart the device.

Solution #5: Revert your Android to its previous version

This is an optional solution for advanced Android users. We know that vanilla and stock Android Oreo versions do not have this problem so there’s a chance that there may be a coding problem with the current firmware version on your phone. This issue is not reported universally so this may be isolated to a specific carrier firmware only. If you know how to flash a firmware, consider rolling the phone’s software to Android 8.0, or to the version that originally came with your S9 when you unboxed it.

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