Huawei+modem+unlocker+v577+work Site
Your modem has newer encryption. Fix: Downgrade the firmware to an older version (e.g., using Balong Flash or Huawei Firmware Finder). This is risky and may brick the modem.
Allows users to manually change the modem's operating mode (e.g., forcing 3G or 4G). Does it actually work? huawei+modem+unlocker+v577+work
Whether the tool "works" for you depends entirely on the and algorithm of your specific modem: Your modem has newer encryption