Thanks for being a part of Samsung community. We do apologize as you are unable to use face unlock security feature. Please follow the below steps to overcome the issue:-
- Navigate to apps >> Settings >> Apps >> Tap on three dots >> Reset app preferences. - Re register the face unlock again. - Please run your device in safe mode.
Be sure to hit ♡ when you find an answer that works for you. For Further assistance, you can get in touch with us via Live Chat option by following- http://livechat.support.samsung.com/Customer_new/IN. You can also connect us via Samsung Members web community by following mentioned url-https://community.samsungmembers.com/en_IN#/
