Downgrading to iOS 12.5 no longer possible on older devices. Although later than one would expect from Apple, the Cupertino-based company released the COVID-19 notification platform to devices that had stayed on iOS 12 in mid-December, such as the iPhone 6, iPhone 5s, and several iPad models. While it is true that the market presence is very low there are still users who continue to use them every day.
Downgrading to iOS 12.5 no longer possible on older devices
A month later, Apple released a new update that solved some of the problems with the notifications of this update. As usual, once a reasonable time has passed, Cupertino has stopped signing iOS 12.5, so it is no longer possible to downgrade to this version, but we can only install iOS 12.5.1.
Although iOS 12 was released more than 2 years ago, Apple continues to offer security updates for both the iPhone 5s and iPhone 6, in addition to the iPad mini 2, mini 3, iPad Air, and iPod touch 6th generation, models that were not updated to iOS 13 and later to iOS 14.
This could be bad news for all those users who have one of these jailbroken devices, but especially for those whose iOS 12.5.1 has not sat well at all. If you are among these users, the best thing to do is to restore your terminal from scratch, deleting all the content you have stored, and restart the setup process.
If the problems are still present, you will have to wait for Apple to release a new version of iOS 12, to see if, with a little luck, the problems that may be experiencing your terminal are solved or visit the Apple support forums to see the problem of your terminal is found in other users and thus be able to find a solution.