Sorry sent before finishing my thoughts. So, here is a list of what might be wrong. It is not usually just one, but a problem with the interacting parts of the system of coil heat, wick, airflow, and characteristics of the liquid such as viscosity and how it vaporizes, which adds the additional interest in the liquid's composition in regards to pg/vg ratio and how the flavoring interacts with the other components of the eliquid.
Therefore, you have to investigate each part of the system. Is your coil working properly? Does it have a resistance compatible with you electronic electrical power delivery system (again a group of interacting components). Is it built to facilitate both the wicking of the juice and the resultant heating and vaporization of said liquid. Think about what a liquid is like on a molecular level. Liquids are composed of molecules that have an electrical afford nigh for each other. They tug and pull on each other and if something is pulling part of the group away they are pulled along in that direction. This is what is occurring during the wicking process which is only a way to pull a liquid in the direction you want it to go. I. Our case in under and around out hot little coil and poof! Off to now being a swarm of tiny blobs of liquid that hav too much energy to lie around and languish in their juicehood.
Will continue discussion in another post if anyone is interested. All you gotta do is understand what is going on in there and systematically examine each of the components as to if they are doing their part in the team effort of delivering that lovely little cloud because as usual you think that size matters but a real cloud dwarfs even something as powerful as ego.