

It’s very very unlikely that your TV and your device connected to it both support and enable ethernet over HDMI by default. But if you are unsure you can test it by connecting and seeing if the TV is getting a connection.
Personally I also opened my TV and disconnected the wifi card since in theory the TV could also just try to connect to any open wifi in the area without me knowing, but to each their own threat model.



You can sniff the network and see if the TV is connecting anywhere.