Normal DFU mode won’t work. We need (kernel-level DFU), which allows unsigned firmwares.
How to downgrade an iPhone from iOS 26 to a previous iOS version 2 Feb 2026 — downgrade ipad 2 ios 9.3.5 to 8.4.1
Check if you have valid SHSH blobs for iOS 8.4.1. Without these, the downgrade stops before it starts. You can use a tool like tsschecker to verify if your blobs are valid for your device's ECID. Normal DFU mode won’t work