Restarting your iPhone is usually straightforward, but it gets a bit trickier if you don't have a working power button.

Quick Answer: To restart your iPhone without the power button, go to Settings > General > Shut Down, then slide to power off.

Instead, Apple added a new security feature in iOS 18.1 that forces iPhones to reboot after a period of inactivity. The change was first pointed out by security researcher Jiska Classen on Mastodon.