Samsung divides its firmware updates using (U1, U2, U3, U4, etc.). The U3 in our keyword refers to the third binary revision . Once a device is updated to U3 firmware (typically Android 10 with the 2020-2021 security patches), it cannot be downgraded to U1 or U2 without severe risks, including hard-bricking the device.
Avoid random “auto patch file.exe” or shady file hosts – they often contain malware. Samsung A105f U3 Auto Patch File
