I have three iphones. 6s, 11 pro and 13 mini. Screens will not lock on any of them. Power button blackens screen - but does not lock. Low Power mode is OFF; Always-on Display is not on; Auto-lock is activated on all three but does not work. The only way to lock phones is to turn them off completely.
[Re-Titled by Moderator]
iPhone 6s, iOS 15
General info on Wake and Unlock: Wake and unlock iPhone - Apple Support
If that is not what you are referring to, and you want to revert to the security state from power-up to just before the first unlock, then you’ll have to restart the iPhone.
If you want to temporarily disable use of Face ID or Touch ID and revert to a passcode prompt, then there are several ways, including tapping the side button five times on various devices, and alternatively use a long press on the side button to trigger SOS mode. In either case, you’ll need to restart-enter the passcode.
Some background: Data Protection classes - Apple Support
Page 105ff: https://help.apple.com/pdf/security/en_US/apple-platform-security-guide.pdf
For how this is expected to work from the perspective of an app developer:
I'm confused by what you think lock the screen means? When you tap the power button and the screen goes black, that is exactly what locking the screen is. Can you explain what you think it should be doing?
How do I fix iPhone screens not locking with the power button?
