I think the problem is not in relaying the message to the device, but in the format of the message.
In the Live data we see a message being sent to the device. But the frm_payload is missing there. (there is one part of the mac_payload, but that is something different).
The device uplinks every 3 minutes. The gateway is running on v2. Which seems not to display the v3 downlink messages (written in this thread: New Application V3 OTAA not working)