I've seen the same thing with my Mavic 2 Pro. Haven't worried too much, as 97, 98% is pretty close to 100! But I've had a controller battery issue in cold weather. In warm weather, the controller battery will outlast three or more drone batteries easily. In cold weather (say, below 20F), the drone batteries were fine, but the controller battery was down to 50% almost immediately, and couldn't handle more than one flight without recharging.