The ethernet speed of the 3rd gen Apple TV 4k(2022) with tvOS 16.2 is limited to 100Mbps. I’m not sure if other peoples experience the same issue. I tested the cable and router with a laptop but all work fine except for the Apple TV. I remember it supported 1Gbps when I got it a month ago.
Definitely gigabit.
I thought the same thing until I realized the default Speedtest server (fastest ping near me I suppose) was limited to only 100Mbps. 🤦‍♂️
Switched to a different server and it's over 950Mbps.