Do not turn off the router during this process to avoid "bricking" the device.
The ZTE ZXHN F680 is a high-performance GPON Optical Network Terminal (ONT) designed for dual-band gigabit fiber-to-the-home (FTTH) connectivity Zte F680 Firmware
After the reboot:
Click , select your downloaded firmware, and hit Upload . Do not turn off the router during this
Maintaining your ZTE F680 GPON gateway with the correct firmware is essential for network stability, security, and performance. As a high-end AC2100 dual-band terminal, the F680 relies on software updates to optimize its MU-MIMO and Beamforming capabilities. select your downloaded firmware
For more information on ZTE F680 firmware and troubleshooting, you can visit the following resources: