My 2016 OLED C6 suffered from some serious unfixable burn in but it was my own fault i would leave the tv on sky news /bbc for hours at a time and say after a year there was permanent burn in of the sky news banner and logo.
Now i have a 2018 OLED and i stay away from these type of channels now and just watch the news online instead lol.
My B7 burned in so hard it melted, 100% OLED light during 16 hours of CNN news did it, I’ve now got an image of Trump permanently on my panel.