The F670L exists in multiple hardware versions, primarily and V9.0 , each with different software paths. Here is a summary of confirmed firmware versions:
Based on community feedback and ISP rollouts, here are the most sought-after stable builds.
Do not turn off the device or unplug the cable during this process. The router will automatically reboot once completed. Conclusion
: The safest method is to visit the ZTE Support Download Portal or the ZTE Enterprise Support page. Search for " ZXHN F670L " to find official packages.