TCL 65US5800 Black Horizontal Line

I have a TCL model 65US5800. Today, a black line like 4-5 inches wide appeared from the top of the TV to the bottom just off center to the left as you are looking at the screen.  It’s faint so you can still watch TV but it is noticeable on white or lighter backgrounds. I’ve turned off the TV and removed all inputs for about 30 minutes before powering on again but that did not help. Thanks for your help.