Do you experience these symptoms if you test your device in safe mode?
-If your phone is misbehaving, it's possible that a third-party app is causing the issue. To figure out what app is acting funny, you can use the Safe Mode feature. In Safe Mode, your phone won't run any third-party apps. This allows you to easily identity and remove the app that may be causing the problem.
Give this link a try to test your device in safe mode:
I have a Samsung Galaxy A71 and I find that my phone has to be held away an arms length and the face unlock works fine. If I have hold it close to my face it doesn't want to unlock. But if I hold it back an arms length it seems to unlock about every time. I think there's some kind of a timer for it so that if your not looking at it in a certain amount of time it won't work. But try to hold it back a ways. I'm not sure if that is a solution but seems to help me with it. Also when I did take the picture used for face unlock I made sure to do it with plenty of light I actually turned on a brighter light and that seems to help it some.
It's odd with face unlock sometimes I will try to use it and it won't work, and lightning has some affect it too. I notice being in a room with low lightning I have trouble a few times. I was out in the sun and it opened quick. I think maybe the one U.I. 2.0 software on the A71 is like that. I'm hoping the one U.I. 2.1 helps out a little with it when we get the update.
Anybody have issue with the Face on unlock slow somtimes, other times doesn't detect face have to try a few different angles then it works??
what carrier? and whats your software version? (setting - about - software info - baseband ver)
mine seems to work fine. never got frustrated for face recognition before..
you can try download samsung members app and submit a ticket there.
try download samsung members app and submit a ticket.
once you open, click +, then click error report
Samsung might be able to tell you if something is wrong with face recognition.