halo tracer twist

I purchased a Halo Tracer Twist from Halo - VW up to 30 watts with a bottom airflow tank - .50 Dual Kanthal Coil - 2300 mAh battery. For some reason, all of a sudden, it stopped firing within the VW range, which I usually keep @ 30watts when I vape, and only works in Bypass Mode. Does anyone...