The USB modem does not work

USB_modeswitch works as expected, the “Eject” command passes, but the NetworkManager does nothing. The GSM connection has been established, but nothing happens. Could it be that the modem supports 2G and 3G, and NetworkManager only 3G?

Notice: In this case, the Ethernet connection works.

I have met similar complaints in other forums. In other Linuxes everything works.