ConkSMASH

So I have a handicapped brother who plays with this tv all day. He is very good with getting into things to the point where I, a fairly tech savvy guy, will scratch my head saying "how the hell did he do that?" When using this tv, he uses the remote from our cable box (Optimum/Samsung) which only controls the power and volume on the tv. But leave it to him to find something to toy with. He found that when the mute button is repeatedly pressed (something he regularly does), this menu pops up. (Pictured below) I don't even know how to access this menu with the factory remote. I figured maybe it was a software glitch, and maybe it would get corrected over time with a software update. So I updated it the other day from 04.00.30 to 04.05.25, but no such luck. I was wondering if anyone had any ideas about if there's a way to disable it. I'm new here so I'm not sure if there's someone in particular I should direct this to that might be really great with the OS and can help.