Hi, i recently purchased the smok tfv12 tank, i installed the Q4 coil, i primed it correctly, but when i started to vape i felt a burnt taste, i lowered the wattage but it was still awful. At that point i thaught that i screwed up, and i burned the coil, when i dissasembled it, it was not burnt not even a light brown color. I noticed that the e liquid looks browner and it smells burnt. I use 20/80 PG/VG e liquid(It states that it is sub ohm E liquid). What can be the problem?