The removal of iOS 13.6 from signing means it’s no longer possible to downgrade to that version.
Apple has stopped signing its iOS 13.6 for the iPhone. Going back to a previous version can be useful for those who have encountered serious bugs or on jailbroken devices.
iOS 13.6.1 is an improvement to its predecessor in a number of ways, including Exposure Notification issues and a glitch that made the screen show a green tint.
iOS 13.6, released in July has a notable feature called Car Key, which allows for digital starting and unlocking of supported vehicles. Also, Apple News+ Audio was released, which brings curated audio stories that are voiced professionally.
As a means to circumvent jailbreaking and give its customers the most stable version, Apple has made previous iOS versions unsigned, which means it’s no longer available to use or download by the public.
iOS 13 was officially announced on 2019 and has undergone several iterations since then.