I purchased 2 boxes of 5 Cleito mesh coils from a seller on ebay. I fitted one as usual, and when I started to vape, it tasted like burning polystyrene.
My liquid is fine as I use it in other machines.
I contacted the seller and he said he had had it before, and gave me a full refund.
I then purchased 2 more boxes from a different seller, guess what, they are the same. He has sent me another 2 boxes to replace them, but they are the same batch number.
All the security numbers check out as authentic.