There can be two things here that went wrong.
A) You did not allow the naptha to fully take in the DMT during the extraction that is why it isn't precipitating it.
B) You did allow the naptha to fully take in the DMT during the extraction so you need to evaporate about half of it before sticking it into the freezer.
So evaporate half of it, refreeze, and if that doesnt help, you need to keep pulling from the base mixture, and possibly changing your technique to make it more thorough.