I'm new to cooking on the BGE and came up with a question. I noticed while cooking a butt that after 8 hours or so, the temperature on my Polder seemed to stop rising. I didn't notice an increase in temperature for an hour or two. I pulled the Polder part way out and slid it back in and the temperature immediately rose 10 degrees. I reinserted it in a different place, again avoiding any bones, and the temperature registered again at the higher temperature. I took off the butt and it was definitely done. Any ideas why I'm getting different readings?