Why do my lines look like this after using the shape tool?
So I'm currently watching and following along with the Envato Tuts+ Adobe Illustrator for Beginners Course and I'm stuck on the custom logo section. I am following the video EXACTLY and get to the point where I select the shape builder tool to delete unnecessary lines, however when I do that the lines don't join up properly. I've started from the beginning multiple times but the lines always look the same and I don't understand what I am doing wrong. I have made sure that the paths intersect at the correct points and experimented with different capping options to no avail. The first screenshot is how it looks on my computer and the second is the tutorial. I would be very grateful if anyone had any suggestions as to why mine doesn't look right. Thanks.

