@FranklyFlawless I’m not sure that I use the latest firmware and the command AT+BMSWVER prints only NO CARRIER in my case:
https://forums.puri.sm/t/sms-received-very-late-modem-sleeping/28722/15?u=gouessej
How can I update the modem firmware under Mobian Linux? Do I still have to contact the support to obtain bm818-tools?