ATT SIM Read Failure but OK with another Carrier

I’m developing LTE communication board with a BG95. I’m having a somewhat strange problem; hope you can help me.

Until the day that I’m writing this, I was working with 2 carriers: ATT and a MVNO(Linksfield). This day, the ATT SIM card is getting an error when the modem is trying to read it. +CME ERROR: 13 and +CME ERROR: 10.

First, I thought that the SIM holder or the BG95 SIM Frontend stop working on its normal operation, but when I changed the SIM to Linksfield everything went well, no error occurred.
So then, now the issue was relying on the ATT SIM card, probably an ESD or something damaged the SIM card. But when I tested the SIM on another LTE board, this worked well.

I have tried more ATT SIMs on the first LTE board and they all have the same problem, it’s like the BG95 can’t read ATT SIMs and can only read Linksfield SIMs.

Can you guess what is happening here? Maybe a configuration that is blocking the read of other SIMs?

Hello Ruben

How about ATT SIM and MVNO SIM powered volotge? and which BG96 FW are you using? query by AT+QGMR.

Linkin WANG