Hi! So I have some possible causes. 1. The cable is loose on either end. But it's probably not that. Make sure you check, though. 2. The cable is broken. If something breaks the cable, it won't work. You can break the inside without the outside showing anything. It happened to me with a charging cable once. 3. The port is broken or dirty. It could be that the ethernet port is just really dirty. If these don't help, then I'd recommend contacting customer support.
