The ZenFone 5Z received Android 10 (Q), but if you participated in the beta program and tried to roll back to Android 9 (Pie) using a simple ZIP, you likely triggered a anti-rollback mechanism. Your device might show "No command" or boot directly to fastboot. Raw firmware is the only fix.
is the ultimate solution to unbrick your phone and restore it back to standard factory settings. What is ASUS RAW Firmware? asus zenfone 5z -zs620kl raw firmware-