You’ve been able to unlock face ID without any problems, but all of a sudden you can’t do it and you’re asked for a passcode. That’s face ID security measures. The probability that someone else can unlock face ID is about one in one million if there is only one face registered, but it is designed to require occasional passcode input for more safety.
When enabling Face ID in the first place, registration of the passcode is considered to be a condition. When the system decides it is necessary, it temporarily stops unlocking face ID and prompts for a passcode.
There are several times when a passcode is requested, and when the iPhone is powered on or restarted, face authentication fails five times. The same is true when you lock in the iCloud iPhone search feature. You must also enter a passcode after displaying the power-off/emergency SOS screen that appears when you press and hold the side button with either of the up and down volume buttons.
These are when the iPhone is unhealthy, face ID is disabled, but there are times when you are asked for a passcode even though there is no clause to think about. One of them is when you’re not using a passcode for about a week.
If your face ID-enabled iPhone doesn’t use a passcode to unlock for the past six and a half days, and you haven’t unlocked with Face ID in the last four hours, you’ll be prompted to enter a passcode. In other words, you have to enter your passcode at least once a week at a pace and once you’ve taken a nap.
Another thing, the iPhone is also required passcode input even when it is not unlocked for more than 48 hours, it may be close to an unusual situation to leave the iPhone for more than two days. Why Does Face ID Not Work!? I wonder, but i still wonder when I’m not using a passcode for about a week.
There seems to be no problem with Face ID, why are you asked to enter a passcode on the lock screen?