Buy an unlocked ONT (like a Huawei or Nokia with open firmware) if you need deep customization. The ZTE F671Y is best left in bridge mode, controlled from a proper router behind it.
: The repack lacks the correct header or is for a different hardware revision (e.g., F670 vs F671Y). Looping Boot : Hold the
The updater blocks older versions. Use a hex editor to find the version string (e.g., "V2.0.1") in the header and change it to "V9.9.9". This is technically cheating the bootloader.