When configuring SMS control, we are using our carrier’s Control Center platform to send the SMS messages as they do not allow external SMS. However, these messages send from a shortcode (four digits), and are not e.164 numbers. These messages are rejected by the Peplink device as they are not the number in the web admin allow list, which requires one to put a + in the string.
I have submitted a ticket (25070676), but wanted to highlight this as many people use IoT through various platforms and carriers that use shortcodes to send network messages (understanding USSDs) origination from the network back to the UE.
In short, anyone using SIMs from a carrier/platform that limit outside SMS but allow platform-generated SMS (i.e., through a portal) won’t work unless the origination number of that SMS is e.164 compliant, or you are not using the allow-list on the device.