Use volume keys to navigate to and press Power to select. Select your downgrade file.
Ensure your phone is charged to at least 15% (ideally higher) to prevent shutdown during the process. Zenfone 5 Firmware Downgrade
Copy the downloaded .zip file into the root directory (main folder) of a MicroSD card. Enter Recovery Mode: Power off the device. Use volume keys to navigate to and press Power to select
You must use firmware that matches your device's SKU (e.g., WW for Worldwide, CN for China). Mixing SKUs will cause failure. Method 1: Using MicroSD Card (Recommended for ZE620KL) WW for Worldwide
Hold simultaneously. Release when the phone vibrates. Flash Firmware: