This is the third time I've cooked a 6lb butt and it stall on me for 8 hours at 160 degrees. This one has been on the egg at 225-245 for nearly 18 hours and is finally up to 191 internal. The first few I did when I got my egg were done in 12-13 hours. Any idea if I'm doing something wrong? Cooking indirect with a pan of water on the placesetter.