first time this ever happened. I had my WFO up to about 800. I used a standard dough recipe, Jim Leahy 18 hour rise recipe. Stretch the dough, put the toppings on, slide it in the oven. In about two minutes, beautiful on top, burned (BLACK) on the bottom.
The only difference i can think of is i used corn meal on the peel instead of my usual semolina.