Setting left margin

I have written 6 books on Writer. I recently installed Kubuntu 15.10, and its version of Writer has a feature that is about to drive me mad. It concerns the ability to drag the left page margin to a point where I want it. Two tiny triangles exist, one pointing up and one pointing down. The one pointing down adjusts the position of a paragraph’s first line. The triangle pointing up adjusts the paragraph’s continuation lines. It appears to me that unless one puts the cursor on just the right point (among an infinity of points) within the lower triangle, it will not move to the right. Until this version of Writer, this problem did not exist. I must have tried 15 to 20 times on each of multiple paragraphs to drag that lower triangle to the right, and it sometimes would move (after several tries) and other times it just refused to move. I finally gave up and went grocery shopping. I’ve been doing this dragging regularly for years without a problem. What may be wrong with 15.10?