iPhone unavailable

There are times the phone will require the passcode, even with FaceID enabled. A few reasons:

• If the phone is restarted
• If the phone hasn’t been unlocked by any means for 12 hours
• If you press the Side button 5 times quickly (a security feature)
• If the screen is getting flakey, or the phone is plugged in with a defective cable (“ghost touch”)
• If the phone has had more than 10 attempts to enter the passcode that failed.

This last can happen if you are in the habit of carrying the phone in your pocket with the screen against your body, and you have Raise to Wake enabled.

If your device has iOS 15.2 or later installed, check out this link→How to reset your iPhone, iPad, or iPod touch when you forgot your passcode - Apple Support. Otherwise:

See this Apple support link→If you forgot the passcode on your iPhone, or your iPhone is disabled - Apple Support

Or watch this companion video ⬇️

After restoring the phone using one of the methods above you can restore your most recent backup.

Well, then most likely you “butt entered” the passcode too many times. You either should turn off raise to wake or carry the phone with the screen away from your body. It may be counterintuitive, as it doesn’t protect the screen as well, but it’s actually more important to protect the back; if the back breaks the phone must be replaced, but the screen can be easily replaced.