I had the same issue with a vivi nova mini and I washed the tank parts and put in the 2.8 ohm with the thicker wicks and the taste went away. I burned that one out and put in a 2.2 or 2.4? And I had the same plasticy taste. It may be the wick material but not 100% sure. You may have to trash that bit of liquid as it may be be contaminated by that flavour. Good luck.