i have new offset smoker. A big backyard type. Thermometers on chamber even with upper tray. I put my remote digital on bottom tray 10 inches lower. Lower temp is 40-60 degrees hotter than upper. Is that normal? If I put my digital on upper tray all thermometers read same. Please help or explain. Here is a photo showing the lower shelf digital over 330 while the upper is showing 230. Say what? What's going on here?