is it possible to get THD greater than 100%?
Yes, it is.
As explained here already, the THD is calculated as sqrt(sum(Vn^2))/V1 for n>=2. This ratio can have any value, because Vn and V1 are totally independent from each other.
A better analysis of your data is only possible if you post your model. Mathematical deductions based on partial screenshots are hard to do.