Nubia Z9 max
Android 5.1.1 Lollypop (play it when tapping on version number in settings).
Has issue with loudspeaker when using phone.
Unlock https://templatemikrotik.com/root-install-twrp-recovery-on-zte-nubia-z9-max/
fastboot oem unlock
TeamWin tool: https://forum.xda-developers.com/t/guide-install-twrp-on-nubia-nx512j-z9max.3638036/