TRM142 – AT+CMGL=4 returns empty OK without listing messages in PDU mode

Hi everyone,

We are integrating the TRM142 modem using PDU mode (AT+CMGF=0).

Issue Details

When executing AT+CMGL=0 (or AT+CMGL=4), if an unread message (UNREAD) is present in Slot 0, the modem immediately aborts the response and returns OK without outputting the +CMGL: header or the PDU data for Slot 0 or any subsequent populated slots.

However, executing direct queries via AT+CMGR=X confirms that the messages are physically stored and readable on the SIM.

Has anyone encountered this issue with AT+CMGL? Is there a known workaround or firmware update to fix message listing?