Temperature in the surroundings, drafts, time to print, structure of the model, changes in the structure as it prints and more are the causes.
There is rarely a magic solution.
You could start by adding mouse ears on the corners (right of toolbar in the prepare tab), these serve to provide more contact and slightly push heat out.
You can change the bed temperature and turn off the fan for the first few layers.
It is about experimentation.
We are as close as it has ever been to having a solution that requires no tweaking to achieve perfection. But, we are not all the way to entirely unattended and perfect output guarantees.