Scrolling in prototype mode to view items - Anyone?

I am trying to set up scrolling for my prototype. I read lots of articles, some make no sense or the functionality is no longer available, but I can’t find a solution to my current problem even after following the step-by-step instructions. The problem is the items scroll out of the top the frame (out of frame screenshot) and the new ones appear at the bottom of the frame (in red) outside of the frame. It looks terrible and I don’t know how to fix it.