[Dekka17]

Hi - I'm an ex Visio user delighted to have a mac OS product. However, I can't seem to figure out how to draw a line connecting one box to another. I can find the line tool, however when I connect them, the boxes become animated and relocate to random places on the page.
My only work around is to "Lock" the two boxes in place and then connect them, but surely that's not the only way to do it. I can see no logical reason why the boxes fly randomly around the page when connected. If I then connect from a second box to a third, same again, they fly around the page. What possible value does this add?
Any ideas?