After releasing the final version of iOS 12.3 to public it looks like Apple has stopped signing iOS 12.2. This essentially means that users can no longer downgrade their iPhone, iPad or iPod touch to iOS 12.2 in case they have upgraded to iOS 12.3 or are using iOS 12.4 beta on their devices. This also means that if you are running a lower version of iOS 12, you can no longer upgrade your device to iOS 12.2, as you will only be able to install iOS 12.3 from now on.
If you are still running iOS 12.2 on your device, then you can head over to Settings > General > Software Update in order to update your device to the latest iOS version. Alternatively, you can upgrade via iTunes automatically or downloading the iOS 12.3 IPSW here.
iOS 12.3 brings a number of new features to iOS including a new TV app, bug fixes and improvements for various features like Apple News+, AirPlay 2, Apple Music, Apple TV Remote, CarPlay and more.
What does this mean for jailbreak users?
If you are a jailbreak user who is jailbroken on iOS 12.1.2 or earlier, then you don’t have to worry about the closing of signing window. You can continue to use your jailbroken device as it is. Since there was no jailbreak available for iOS 12.2 anyway, jailbreak users are better off staying at iOS 12.1.2 or lower for now.
However if you are someone who is still running iOS 12.2 and would like to get a chance at jailbreaking his or her iPhone or iPad in the near future, then it is advisable to stay at iOS 12.2 and not upgrade to iOS 12.3. It is more likely that jailbreak developers will add support for iOS 12.2 when compared to iOS 12.3, which may not get a public jailbreak in the near future.