BG95-M3 Loosing AT command socket when SIM card is unocked

I have a nasty issue: I try to use a BG95-M3 with an EVB.
Whenever I unlocked the SIM the screen freezes, as if the USB-UART is not active anymore.
When requesting the status the USB sockets are still there but no interaction is possible.

I removed the SIM-lock and now the unit goes directly into this mode.
No possibility to send anything to the socket.

I tried the SIM in an android smartphone, it works perfect.
enabling the SIM-lock again brings back the possibility to send AT commands
but sending AT+CPIN=“pin#” kills the socket

Hi

How did lock SIM? if possible to share any AT commands for us? we did on EVB but everything are good.

B R
Linkin WANG

I did the PIN removal and reset on a smartphone. (S10 Android 12, Kernel 4.14.113-25257816)

Strange thing is that on a W10 station, the AT socket remains alive over the PIN actions.
On an Ubuntu desktop the same.
So it must be something in the OS of the beaglebone black.
I will experiment more to find out where it goes wrong.
Keep you updated