help with modem/gateway fxt009

I am using a modem/gateway fxt009 and i can’t register in a network with the gateway(the red one) using AT comands, I always get creg 0,0, but the led is flashing slowly, i can’t understand it.
I tried to register using COPS=0,2,21403, but i doesn’t work.
Also i tried with different SIM cards, and i put it in a programmable extendable modem(the blue one) and it works correctly.
Thanks for your help

Eh :question: