Device being seen by gateway but not updating status/data

Hi,
I had a couple of devices setup and working in the past. After a few months I went back to them, and it looks like they are not updating information. The strange thing is that if I go to https://console.thethingsnetwork.org/gateways/{name}/traffic I see downlink traffic coming from a specific device.

But if I then go to https://console.thethingsnetwork.org/applications/{name}/devices/{name}
The last seen status is 8 months ago, and inside the data tab, everything is empty.

What could be going on?

Thank you!