It looks like a faulty panel. Would recommend getting a new one. What is the model number of the tv?
My old tv was getting like that and eventually it went totally white screen.
Good thing you have other people who actually know what it is or might be. I was literally about to say you have the manual up, I have no tech smarts. Which is odd because as many video games as I play you’d think I would know at least a little about tech
Warranty?