After installing the firmware, follow these steps:
Community members on forums often recommend V1.10.23 as the most stable firmware for this device. zlt x21 firmware download exclusive
Some exclusive builds unlock the hidden SMS gateway and enable VoLTE switches that carriers disabled. After installing the firmware, follow these steps: Community
For VN007+ users, once you upgrade to version 1.15.1 or higher, you cannot safely revert to an older version . After installing the firmware