ZTE stopped providing official OTA updates for the 9030 line around 2019. The final official build is usually Android 7.1.1 with a security patch dated 2018-12-01.
This often resolves 50% of "firmware corruption" claims. Zte 9030 Firmware
ZTE Blade V30 - Full specifications, price and reviews - Kalvo ZTE stopped providing official OTA updates for the