I have been having the same problem. Although, I am positive that my issue is bad coils. I purchased 3 5-pack boxes and two of those boxes both had at least 3-4 bad coils in them. The one box, every coil has lasted me at least a week. I vape at 15w on a 1.8 ohm coil. If you google "bad nautilus coils" you will see a lot of posts about this problem lately. However 20w is a bit high. I wouldn't go that high myself, so that may be your issue.