TTN console Uplink returns empty Payload

Sorry, beginner question…
I am connecting a LoPy to TTN via OTAA. I am sending a integer of the temperature in the payload (which is converted to bytes using the micropython lora socket object’s send function method). The sensor and node all work correctly.

The node’s application on the console shows the device activating, then the uplink occurs a few seconds later.

The Payload in the uplink however shows nothing (00000000000000000000000000).

Have I forgotten something really obvious?