Pit Boss extreme heat above 500 when it was set to 400. Smoking a lot. And I think caught fire in the feeder tube.

Has anything like this happened to anyone? The temp was set to 400 and I came out about 12 minutes later and it read 546 w lots of smoke. I turned it off and then unplugged it and am just letting it cool down now. I also never opened the latch to be safe. Thoughts on what happened and/ or how to fix the issue?