I am guessing that you may have used too much flavor. Flavoring is funny. Most taste really good at a certain % but move up beyond that point and it will taste perfumey or down right bad.
I just saw your post on the Vivi Nova. I have always had flavors muted by using similar and I would move on to a different atty or carto before upping my flavor to as much as 30% but that may just be me. Good luck!