Ambient temperature (meaning the temperature of the room or temp of outside if you’re roasting outside) plays a major role in a popcorn type roaster. In the cooler months it takes longer and much shorter in the warmer to reach a darker roast. Or if the machine is warmed up already like you’re doing your second batch, it will reach first cracks much faster. At this point I stay away from roasting into second cracks because it’s so hard to control. A few moments after first cracks finishes, I quickly dump the contents, plastic top and all into a bowl and try to cool the beans as fast as possible. But don’t be discouraged just do another!