So I just purchased the Smok Prince tank and I’m using the Q4 coil first. The juice is Cheech and Chong dope deal which is a Nutella banana in 3mg 70vg/30pg. I’m on day 2 of this coil and still vaping strong at 55wv I noticed some dark residue on the top of chimney so I got a qtip and cleaned it down to the coil. When I took it out it was dark brown/black. It has not had one burnt or dry hit. Could this just be gunk build up or is the coil burning and I’m just not tasting it?