After buying a Maverick T-33, I have discovered that the internal temp in my Bradley 4 rack fluctuates wildly. I was smoking a prime rib,and had to set oven temp at 190c,to get to the desired range of 225c. It would climb to 244 before coming back down to 190, then climbed back to 244 over and over. This seems to be a dramatic change ratio. Does anyone know if this is normal for an electric smoker?