Enable and OEM Unlocking within the Android Developer Options.
A bead of sweat rolled down his temple. If this failed, the tablet would be permanently locked, a paperweight forever. The MTK security was notoriously finicky. mtk imei v30
Newer Android versions have enhanced security features like hardware-backed attestation and verified boot that may reject IMEI changes. Some devices also have encrypted NVRAM partitions. In such cases: Enable and OEM Unlocking within the Android Developer