Oh my, until that last line the answer seemed so easy. Replacing an electronic device that acting up so soon and in such a significant way seems like a no-brainer to me.
But... you could try contacting the TV manufacturer or seeing if they have a forum. Who made it? There's usually a phone number and/or website for support in the box. Of course, it's obviously well within the warranty period, but that's usually a much slower way to get anything done.
Some people have reported that TCL told them to leave the TV unplugged for 10 minutes and then plug it back in, and that worked, but if that happened on the first day, I'd be wondering how often I'm going to have to do that...
