Recently purchased some Ikenvape 510 Mega-fusion LR punched cartos and also some Smoktech LR cartos. Just received some new juices from Mt. Baker and after filling cartos (both) and using them for a day or two getting burnt taste and filler turning a dark color. I have not had this problem before but my wife has had this happen and I thought it was the juices she was using. Want to get this figured out so I don't ruin anymore cartos if I need to change something. When I fill the cartos I fill until juice starts coming from holes then sit for awhile. When I start using them I vape about 3.3-3.5 on Itaste MVP or Ego twist..