My guess is that you have the power level set to high for the coil+wicking your using.
My theory is that many of these modern TC APV's assume some thermal mass of the wick+
juice exists and while it is firing to the temperature set point it is measuring how much energy equates to how much temperature rise in the coil. (with me so far?)
(as an example) With the coil half (or mostly) submerged in water the power to temperature slope will be even during the ramp to the temperature set point. However if you were to suddenly remove the coil from the water the thermal mass of the water goes away and the temperature rise slope will skyrocket as the coil is no longer having to heat up the water.
The same goes for our coils+wicking. If the wick in contact with the coil becomes dry the thermal resistance will go down and the heating slop will sky rocket and many of the modern TC MOD's will start displaying "dry coil" messages and cut the power off.
The simple solution is to use a lower power setting. Smaller wire will heat/cool much faster than larger wire. Hence big coils with >25AWG wire (6 windings) have more thermal mass to heat+cool than <28AWG wire (6 windings) .
While my iStick TC40 will fire @ 40W from the get-go (as long as my coil has a >=0.15ohm resistance) and hit its "temp protect", both my YiHi powered devices can act in a similar way with "dry coil" messages if I have the Joules set to high.
Easily avoidable on many modern TC mods.
