A newly discovered iOS 27 bug can temporarily soft-lock an iPhone with a quick sequence of swipes, and the trick is already spreading on social media as a prank. The glitch makes home-screen swipes and many taps unresponsive, while the power-off slider may also stop working.
Fortunately, the issue is only a temporary software lock and does not permanently brick the device. A force restart restores the iPhone to normal, and Apple is expected to fix the bug in a future software update.
Source: 9to5Mac