pen tool puts all vertex points on same position as the first one

I wan to make a mask on a layer with the pen tool, however, every time I set a new vertex point, it just adds it on the same position as the first one I put. Some times it puts a new vertex point in a place I didn't click on.
It doesn't happen when I use the pen tool to draw a shape.

I have the newest version of Adobe AE. Actually, I updated it a week ago. Is there a bug in the newest version?