Sketching a line from a circle's perimeter?

Hi all,

I'm trying to sketch a line starting from a certain point on the perimeter of a circle. However, when I click to do so, the first endpoint of the line jumps to a seemingly random point in the circle. I've tried several times, but this is happening pretty consistently.

Any help is appreciated!

Thanks in advance,

SolidworksModeling And Assemblies