I get locked out of Face ID from my iPhone intermittently, which has happened over the last couple of years when running iOS 14, 15 and 16. This is after Face ID was used and the iPhone was locked.

It happened again this morning after I upgraded to iOS 16, last night and was playing around with it. It even happened during a flight in airplane mode. I am wondering if anyone knows what would cause that to happen, other than turning the phone back on after a power down, or not using Face ID continuously for over 48 hours.