Modem manager now supports cell broadcast messages, see: https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/issues/253 However, that also needs support in client applications, because ModemManager treats this as a completely separate new object. E.g., this was added to Phosh for it: https://gitlab.gnome.org/World/Phosh/phosh/-/merge_requests/1334 (Why not in Chatty? Don't ask me…) Either Spacebar or something else in Plasma Mobile needs to handle this.