I was told that by joining paths would help fix the thinner line at the end of the semi-circle. This is a zoomed in version to show what I'm talking about. You can barely see it, but you get the idea. When zoomed out in the PDF file, the line of the semi-circle is thinner than the straight line on the right. BUT, in InDesign it looks normal.
But when I try to join the paths, the semi-circle gets bent: