I'm having problems with the Kanger T3S mouthpieces' cracking. I have gone through 6 T3S bodies in the last 2 months. they are cracking from where the inter stainless tube ends to the mouthpiece ! I am only using Saffire tobacco 6, 6mg ! Which is Propylene Glycol (50%), Vegetable Glycerin (50%), Nicotine (6%). I have some that I have been using for 3 years and are fine. And I always use ST6, 6mg. Any suggestions ?? This gets costly !