Apple has issued an update to the iPhone and iPad in the form of iOS 11.3.1 that fixes an issue with the iPhone 8. When users would get their screens replaced by third-parties, the device became unresponsive. This apparently was a software issue and Apple has resolved it in today’s upgrade.
No other fixes are noted in today’s release notes.
To install the update, head over to Settings > General > Software Update. Tap “Download and install” next to the iOS 11.3.1 listing and you’ll be good to go. I recommend jumping on a Wi-Fi network first alongside plugging in your device beforehand as a) you don’t want data overcharges on your bill and b) you don’t want your phone or tablet to die during the installation process.