I had a similar situation. I am only 66% Central European while being 22% Scandavian and 12% Finnish-Volga/Ural. I have traced all my family lines back at least 300 years and some back 500 years with all ancestors living in Germany, Luxembourg and Switzerland. So I was very suprised to have 1/3 of my DNA from regions I have never found a connection to. It must be from 500-1000 years ago or more.