It’s part of the TCL hidden service menu. There’s a key combination you can enter on your remote to access it, but it varies by model, so so a bit of googling around.
From what I’ve read, it persists through factory resets, but can be turned off just fine in that menu.
I’m seeing lots of these posts lately, so I’m really not sure how people keep activating this seeing as it’s pretty buried in menus. Makes me think there’s an issue in a system update they’re pushing out.
Try pressing mute