Do not flash older raw firmware (e.g., Android 8) if you have already updated your bootloader to a newer version via OTA. This can cause a "anti-rollback" brick. ASUS enabled rollback_index protection starting with Android 9.
: Verify your build number in Settings > About > Software information to ensure you aren't attempting an unsupported downgrade without the proper raw version. asus zenfone 5z -zs620kl raw firmware-
: Specifically version 1.0.0.45 or newer is often recommended for the 5Z. Do not flash older raw firmware (e
[29]. This means that if your device is currently locked, it may be impossible to flash certain types of raw firmware or custom software that requires an unlocked state. if your phone is still functional? asus zenfone 5z -zs620kl raw firmware-