Go to Settings > AT&T Software Update > Check for Updates . Offline Update Method:
GSIs are only recommended for experimental use or if you intend to use the Axon M strictly as a traditional single-screen phone with updated security patches. Rooting and Stock-Based Modification zte axon m z999 firmware best
Official Stock ROM (.zip for Local OTA / QFIL MBN format) Why Choosing the Right Firmware Matters Go to Settings > AT&T Software Update > Check for Updates
If your device is stuck in an infinite bootloop or won't power past the AT&T logo, you must use a PC to flash the raw firmware via Emergency Download Mode (EDL). zte axon m z999 firmware best
Ensure the update.zip is not zipped inside another folder.