Hello I just got my brand new anyvape anymod in the mail. At first it was working great but now has stopped. On high wattage there simply isn't the vapor production and vapor is a cool temperature (I'm talking 18 watts). It's not my tank or coil as they are brand new and work perfect on my other devices. Neither is it the battery as I went out and bought a brand new 3100 mah 18650 purple efest from my reputable local vape shop. I did notice however there is a brown residue all around the outer rim of my centre post. Could this be the reason for the lack of production? Please help, greatly appreciated.