So, I have a BBQPRO Charcoal Grill with a smoker box. I have used it 3 times and each time I have to fight to keep the temp even close to 200 degrees. I have used hickory chucks with lump charcoal and just straight charcoal. The door between the smoker box and barrel is open. I just installed a duct to extend the chimney down lower to the cooking surface to try and get the temp up. That didn't help. Any tips would be a great help.