Apple has released iOS 11.2.1 which addresses bugs and issues that have been discovered since the release of iOS 11.2. According to Apple’s release notes, the update addresses an issue that could disable remote access to shared users of the Home app. Apple broke remote access for shared users when implementing a fix for a major HomeKit vulnerability. The iOS 11.2.1 update can be downloaded for free on all eligible devices over-the-air in the Settings app.
To access the update, go to Settings –> General –> Software Update. if you have been running Apple’s Beta you will have to remove the beta profile to see this update.