I've had some intermittent temp fluctuations, typically reinsert probe connector fixed. However, the probe ended up giving out. RT sent me a new one at no charge. New one is longer which I really like. That one I now use on the item closest to the stack.
I quit the beer can and spatchcock methods. I've been doing my whole chickens on their backs at 350F for 90-120 mins (165F IT). Clean, season, stuff cavity with fresh herbs (<--- important) and cook. Doesn't get any easier! Results are great.