Well you could not connect it to the internet…

Maybe you’d disable it on the settings, but it remains enabled anyways. Then it would detect an open wifi and connect autimatically.

Or maybe the software that comes with it is buggy as hell your HDMI framerate and resolution became affected.

A wifi antenna should be easy to find.

If you cut it, could it lead to an error, or just weaken the signal?

If you wrap the TV in tinfoil, it’ll be a faraday cage and block all WiFi