Apple support and code signing for iOS 13.6.1 stops, which means it is not possible anymore for users to downgrade from iOS 13.7.
Apple released the iOS 13.7 update for everyone recently. One of the most notable features of the update is that it allows you to opt-in to Apple's COVID-19 Exposure Notifications system without downloading an app. One week after the update, Apple ceased to sign iOS 13.6.1, which made it impossible for users to downgrade from iOS 13.7 to iOS 13.6.1.
There is no clear reason why the Cupertino-based company blocks users from downgrading iOS 13.7 to iOS 13.6.1. The reason might have something to do with security or perhaps Apple just does not want to support older iOS versions simply because it does not want to deal with bugs that were already addressed by the new update. For one, the 13.7 update includes a major enhancement of the COVID-19 Exposure Notifications.
With the iOS 13.7 update, users can now directly enable COVID-19 Exposure Notifications using their iPhone's Settings app. Enabling this option allows your iPhone to start its monitoring process using Bluetooth technology and record possible exposures so you are readily informed of a likely COVID-19 exposure based on the procedures and guidelines put in place by your local public health authority. If Apple allows users to downgrade from iOS 13.7 to iOS 13.6.1, this new enhancement will not be available to them.
In the case of the iOS 13.6.1, Apple revealed that the version, which they released in August, had issues with the COVID-19 Exposure Notifications, something that the tech giant needed to fix immediately because of the prevailing situation. Another issue with the version is it appears to add a green tint to the displays. Since the bugs are already fixed with the new update, Apple perhaps did not see any need for users to downgrade from iOS 13.7 to iOS 13.6.1.
Before the discovery of bugs relating to the COVID-19 Exposure Notifications and the iOS 13.6.1 version, some users, particularly those who own jailbroken devices, commonly downgrade to older iOS builds. In some instances, Apple users find it necessary for them to downgrade from iOS 13.7 to iOS 13.6.1 once they experienced or discovered considerable bugs after they upgraded to the latest iOS build.
However, since older iOS versions have issues with the COVID-19 Exposure Notifications, Apple saw the need to make the update. Now that the company has ceased signing the old iOS build, users are now prevented to downgrade from iOS 13.7 to iOS 13.6.1. According to Apple, this is one of the necessary ways to ensure that customers have the most stable experience when it comes to using iOS devices.
