Hi @Juan_Cossio,
I would recommend first looking at any _health.qo Notes that should appear after your Notecard reconnects. They may give some hints as to why the previous connection failed. It’s also important to understand the Notecard Penalty Boxes that will protect your device/battery in the event that Notecard is unable to establish a cellular connection.
Is your device in continuous mode (via the hub.set request)? Are you on a recent release of the Notecard firmware? If it happens again there are commands like hub.status, hub.sync.status, and card.wireless that can help diagnose the current status of the Notecard and its connection to Notehub.
Rob