Your fontstrings aren't fully anchored. They only have 1 point anchored TOPLEFT.
They should also anchor on the right side of the scrollframe
Code:
if i == 1 then
self.ScrollFrame.List[i]:SetPoint("TOPLEFT",self.ScrollFrame,"TOPLEFT",5,-5)
else
self.ScrollFrame.List[i]:SetPoint("TOPLEFT",self.ScrollFrame.List[i - 1],"BOTTOMLEFT",0,0)
end
self.ScrollFrame.List[i]:SetPoint("RIGHT",self.ScrollFrame)