The DNA boards are very sentitve. Unlike most temp control devices, it reacts differently dependant on the material. For example in most TC mods you just set your temp and lock your resistance whether you have a 316 or Ni200 build. With a DNA chip, it fluctuates massively and the standard preheat pretty much burns the cotton regardless of the temp you set it to.
You need to remember to, the DNA boards were designed with temp control in mind and for avid vapers. As such you need to use escribe to make the most out of it.
I found with my DNA 200, I always use steam engine to find the temp graph for the build I have, download it then import it into escribe. Usually set it in the middle of hard and soft and preheat for 1 second at 50w.
If you're relatively new at this, lemme know and I'll post a tutorial.