I just downloaded synfig and I have no clue what I’m actually supposed to do. I wanted to draw a banana. So I went to the draw tool and made a curved line, y’know, like a banana. As soon as I click out of the drawing, it disappears. The hell? This shit is so confusing, Why does it make 10 new layers for every new line I draw, that just disappears every time I click out of it anyway? I’m using version 1.0.2 if that helps.
Hello and welcome here…
Synfig has is own way of doing things… and hopefully synfig also had a step by step manual 
for your precise question take a look to the wheel icon in the option tool panel, it’s not a bug, don’t need to upgrade for that case.