I have an Arduino MKR1500 NB board with SARA-R410M modem. Firstly I used with a Vodafone NB-IOT sim card, with this working well without issues.
But If I insert a different NB-IOT sim cards, it freeze after 5-10 sec and doesn’t response answer to AT commands. I have a telekom and hologram sim card.
I have a SIMCOM 7020 modem and in this working perfectly all sim so the cards are ok!
Revision: L0.0.00.00.05.08 [Apr 17 2019 19:34:02]
I wrote to Arduino forum as well, but I think it’s a modem issue, not the Arduino, because I use only AT commands, not the complex code for it.
Does anyone have any idea what could be wrong?