Can't register SIM card on GSM Module (SIM800)

I am using the following quickstart guide: https://www.ayomaonline.com/programming/quickstart-sim800-sim800l-with-arduino

I have tried different sim cards (confirming that they work by testing them in a mobile phone) but I cannot get them to register on the SIM800 module.

This is the module that I am using: https://www.aliexpress.com/item/SIM800L-V2-0-5V-Wireless-GSM-GPRS-MODULE-Quad-Band-W-Antenna-Cable-Cap/32877115526.html

The following are the AT commands and outputs:

AT+COPS=?
+COPS: (3,"VODAFONE","voda NZ","53001"),,(0-4),(0-2)
OK

AT+CFUN?
+CFUN: 1
OK

AT+CREG?
+CREG: 0,0
OK

I have checked power supply and that is fine. Any other ideas?

Hi abasel, i have the same problem. forgive my poor English.
I worked before with sim900 which is basically the same but older, withouth problems. I have done projects of iot, etc. The new sim800l modules i am testing, the most typical:



I've tried with movistar and vodafone sim, with the same results. I cant register to gsm and i only fin one operator , I suppose it will be fictitious (is not within reach of my MT, according to my other sim900 module). Amena in this case:

AT+COPS=?
+COPS: (3,"Retevision Movil","AMENA","21403"),,(0-4),(0-2)

OK

in both modules, with both SIM´s ¿?
Of course, VCC ok, sim pin ok, band ok, signal ok:

AT+CBC
+CBC: 0,94,4153

OK

AT+CPIN?
+CPIN: READY

OK

AT+CSQ
+CSQ: 26,0

OK

AT+CBAND?
+CBAND: EGSM_MODE,ALL_BAND

OK

I've been trying for a week to register it on the gprs network, with no results. I'm starting to think that it's incompatible with certain types of sim cards.
Have you achieved anything since your last post?