When I use TC mode, why the device switch to VW mode?

A lot of vapers have a problem that when they use TC mode the device switch to VW mode. What's happening is that the mod didn't see enough resistance change when the coil is heating up.

Thus, please check the atomizer head you use. If you use Kanthal coil under TC mode, the device will jump to VW mode. When using TC mode, please use Ni 200/Ti/SS and other Temp control coil in the atomizer.