I think it's just timeout of few days. Point is that if your phone got stolen or taken away from you, attackers have a limited time to attempt a fingerprint att

I think it's just timeout of few days. Point is that if your phone got stolen or taken away from you, attackers have a limited time to attempt a fingerprint attack, after which they must use more sophisticated pin bruteforce attack. Not sure if it adds much to security, but it's something.