With us, the bottom two rows of stones were completely wet. Now the roof has been on for about 3 weeks and is also watertight, and the windows have been installed. The front door is not yet in, and our basement is dry. Our site manager as well as the masons (both around 60 years old with a lot of experience) said that it is completely normal for the basement to be wet in the shell construction and that everything dries on its own. I would not worry about that.