Resistance Lock is part of the firmware on most TC mods. The principle as it was learned from the first generations of TC mods, first DNA40 chips and similar had a hard time, TC is just a real time reading of the resistance of the wire hundreds of times a second/minute, resistance increases as the wire gets warmer and resistance decreases as the wire cools. Some of these earlier TC control boards and some of the current cheaper control boards, once resistance reaches example a 0.15ohm (first cold reading) Ni200 Nickel coil, after about 3 to 4 consecutive firings that coil is now reading 0.35ohms at cool level, next firing that cool resistance gets to be about 0.55ohms, next firing control board kicks out of TC mode into wattage mode, the coil above the programmed TC algorithm threshold by the board's logic, still the same 0.15ohm coil, but the control board doesn't think it is. Thus TC resistance lock was added in, locking the TC resistance algorithm variable for "Cold" coil in, even the coil is warm at 0.23ohms, it takes the variance between cold and current, this example 0.08ohm variance, coil not at room temperature it is approximately around 130F or so. Some mods, I think the first gen of the Cubiod suffers this, even if the resistance is locked in it will still kick out of TC mode sometimes with Titanium and Stainless Steel TC coils, SS coils there is no problem as it can run in TC or standard wattage mode no problem, it is Ni200 (Nickel) and Titanium that can't, get them to hot and they'll either melt down and/or at toxins into the vape like Titanium Dioxide (Ti wire). Best advice I tell customers, remove the tank/atomizer with a TC coil or change the coil, unlock the TC Resistance lock, re-read the coil, and lock it back in. I have an Evic VTC Mini, pretty much the same firmware as the cuboid, remove my TC atomizers it stores the resistance lock in memory, next time the atomizer is attached it is still at the original cold TC lock reading and still locked, have to unlock it, re-read and lock it back in again. As wire is heated and cooled it ages and is worked just like bending a piece of metal back and forth until it snaps thus tempering it harder or annealing it softer depending on the metal, so over time resistance changes, most times increasing ever so gradually, and why I suggest re-reading TC locked coils every once in a while.
