When the bisquette burner is fully heated you should start seeing wisp of smoke within a minute, but if it is not fully preheated by the time the first bisquette lands on the burner, it will sit there for at least 5 - 10 minutes before it gets hot enough to smoke the bisquette. Not preheating the burner, you will not fully burn that first bisquette.
When you preheat the smoker, also turn on the bisquette burner at the same time, but don't load any bisquettes at that time. When you are ready to put food in the smoker reset the smoke time, and load the bisquettes. The burner will be hot and the first bisquette will start smoking immediately.